Category: Class 10

AP State Board Syllabus AP SSC 10th Class Chemistry Solutions Chapter 10 Chemical Bonding Textbook Questions and Answers.

AP State Syllabus SSC 10th Class Chemistry Solutions 10th Lesson Chemical Bonding

10th Class Chemistry 10th Lesson Chemical Bonding Textbook Questions and Answers

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Question 1.
List the factors that determine the type of bond that will be formed between two atoms. (AS1)
(OR)
How can you identify the type of bond formation between two atoms?
Answer:

• The strength of attraction or repulsion between atoms.
• Electrons in valence shell (valence electrons).

Question 2.
Explain the difference between the valence electrons and the covalency of an element. (AS1)
(OR)
How are valence electrons different from the covalency of element? Explain with examples.
Answer:
Valence electrons :

• Number of electrons in the outermost orbit or an atom is called its valence electrons.
• Ex: Na (Z = 11). It has 2e^– in I orbit, 8e^– in II orbit and 1e^– in III orbit.
• So number of valence electrons in Na atom are ‘l’.

Covalency of an element:

• Number of valance electrons which are taking part in covalent bond is called covalency.
• The electron configuration of Boran is 1s² 2s² 2p¹.
• It has three valance electrons.
• So its covalency is 3.

Question 3.
A chemical compound has the following Lewis notation : (AS1)
a) How many valence electrons does element Y have?
b) What is the valency of element Y?
c) What is the valency of element X?
d) How many covalent bonds are there in the molecule?
e) Suggest a name for the elements X and Y.

Answer:
a) 6
b) 2
c) 1
d) two
e) X – is hydrogen and Y – is oxygen. The formed molecule is H₂O.

Question 4.
Why do only valence electrons involve in bond formation? Why not electron of inner shells? Explain. (AS1)
(OR)
Which shell electrons involve in bond formation? Explain. What is the reason behind it?
Answer:

• The nucleus and the electrons in the inner shell remain unaffected when atoms come close together.
• But the electrons in the outermost shell (valence shell) of atoms get affected.
• The inner shell electrons are strongly attracted by the nucleus when compared to the valence electrons.
• So electrons in valence shell (valence electrons) are responsible for the formation of bond between atoms.

Question 5.
Explain the formation of sodium chloride and calcium oxide on the basis of the concept of electron transfer from one atom to another atom. (AS1)
(OR)
Explain the formation of any two compounds according to Kossel’s theory.
Answer:
I. Formation of sodium chloride (NaCl) :
1) Sodium chloride is formed from the elements sodium (Na) and chlorine (Cl).

2) Cation formation:
i) When sodium (Na) atom loses one electron to get octet electron configuration, it forms a cation (Na⁺).
ii) Now Na⁺ gets electron configuration that of Neon (Ne) atom.

3) Anion Formation :
i) Chlorine has shortage of one electron to get octet in its valence shell.
ii) So it gains the electron that was lost by Na to form anion and gets electron configuration of Argon (Ar).

4) Formation of NaCl :
i) Transfer of electrons between ‘Na’ and ‘Cl’ atoms, results in the formation of ‘Na⁺‘ and ‘Cl^–’ ions.
ii) These oppositely charged ions get attracted towards each other due to electrostatic forces and form the compound sodium chloride (NaCl).
Na⁺_(g) + Cl^–(g) → Na⁺Cl^–_(s) or NaCl

II. Formation of calcium oxide (CaO) :
1. Calcium (Ca) reacts with oxygen (0) to form an ionic compound calcium oxide (CaO).

2. Atomic number of Calcium is 20. Its electronic configuration is 2, 8, 8, 2.
3.

4. Atomic number of Oxygen is 8. Its electronic configuration is 2, 6.

5.

6. These oppositely charged ions get attracted towards each other due to electrostatic forces and form the compound calcium oxide (CaO).
Ca²⁺ + O^2- → Ca²⁺O^2- (or) CaO

Question 6.
A, B and C are three elements with atomic number 6, 11 and 17 respectively.
i) Which of these cannot form ionic bond? Why? (AS1)
ii) Which of these cannot form covalent bond? Why? (AS1)
iii) Which of these can form ionic as well as covalent bonds? (AS1)
Answer:
i) ‘A’ cannot form ionic bond. Its valence electrons are 4. It is difficult to lose or gain 4e^– to get octet configuration. So it forms covalent bond [Z of A is 6 so it is carbon (C)].

ii) ‘B’ cannot form covalent bond. Its valence electrons are 1 only. So it is easy to donate for other atom and become an ion. So it can form ionic bond [Z of B is 11, so it is sodium (Na)].

iii) Element C can form ionic as well as covalent bonds. Atomic number of Cl is 17. It is able to participate with Na in ionic bond and with hydrogen in HCl molecule as covalent bond.

Question 7.
How do bond energies and bond lengths of molecule help us in predicting their chemical properties? Explain with examples. (AS1)
(OR)
How can you explain with examples that bond energies and bond lengths are used to recognise chemical properties?
Answer:
1. Bond length :
Bond length or bond distance is the equilibrium distance between the nuclei of two atoms which form a covalent bond.

2. Bond energy :
Bond energy or bond dissociation energy is the energy needed to break a covalent bond between two atoms of a diatomic covalent compound in its gaseous state.

3. If the nature of the bond between the same two atoms changes the bond length also changes. For example, the bond lengths between two carbon atoms are C – C > C = C > C = C.

4. Thus the various bond lengths between the two carbon atoms are in ethane 1.54 Å, ethylene 1.34 Å, acetylene 1.20 Å.

5. The bond lengths between two oxygen atoms are in H₂O₂ (O – O) is 1.48 Å and in O₂ (O = O) is 1.21 Å.
6. Observe the table.

7. When bond length decreases, then bond dissociation energy increases.

8. When bond length increases, then bond dissociation energy decreases.

9. Bond length of H – H in H₂ molecule is 0.74 Å and its bond dissociation energy is 436 KJ/mol, whereas bond length of F – F in F₂ molecule is 1.44 Å and its bond dissociation energy is 159 KJ/mol.

10. Melting and boiling points of substances also can be determined by this bond energies and bond lengths.

Question 8.
Predict the reasons for low melting point for covalent compounds when compared with ionic compounds. (AS2)
(OR)
“Covalent compounds have low melting point.” What Is the reason for this statement? Explain.
Answer:
They are covalent compounds.

• The melting point is low due to the weak Vander Waal’s forces of attractions between the covalent molecules.
• The force of attraction between the molecules of a covalent compound is very weak.
• Only a small amount of heat energy is required to break these weak molecular forces, due to which covalent compounds have low melting points and low boiling points.
• Please note that some of the covalent solids like diamond and graphite have, however very high melting points and boiling points.

Question 9.
Collect the information about properties and uses of covalent compounds and prepare a report. (AS4)
(OR)
Generally these compounds are non-polar in nature. What are those compounds? Explain their properties and uses.
(OR)
Write any two uses and two properties of covalent compounds.
Answer:
The compounds are covalent.
Properties of covalent compounds :

1. Covalent compounds are usually liquids or gases, only some of them are solids.
2. The covalent compounds are usually liquids or gases due to the weak force of attraction between their molecules.
3. Covalent compounds have usually low melting and low boiling points.
4. Covalent compounds are usually in soluble in water but they are soluble in organic solvents.
5. Covalent compounds do not conduct electricity.

Uses of covalent compounds :

1. Covalent compounds form 99% of our body.
2. Water is a covalent compound. We know its many uses.
3. Sugars, food substances, tea and coffee are all covalent compounds.
4. Air we breathe in contains covalent molecules of oxygen and nitrogen.
5. Almost everything on earth other than most simple in organic salts are covalent.

Question 10.
Draw simple diagrams to show how electrons are arranged in the following covalent molecules : (AS5)
a) Calcium oxide (CaO)
b) Water (H₂O)
c) Chlorine (Cl₂)
Answer:
a) Calcium oxide (CaO) :

b) Water (H₂O):

The formation of water molecule can be shown like this also

c) Chlorine (Cl₂):

We can explain the formation of Cl₂ molecule in this way also.

Question 11.
Represent the molecule H₂O using Lewis notation. (AS5)
(OR)
How can you explain the formation of H₂O molecule using dot structure?
Answer:
One atom of oxygen shares its two electrons with two hydrogen atoms to form a water molecule.

Question 12.
Represent each of the following atoms using Lewis notation : (AS5)
a) Beryllium
b) Calcium
c) Lithium
Answer:

Question 13.
Represent each of the following molecules using Lewis notation : (AS5)
a) Bromine gas (Br2)
b) Calcium chloride (CaCl₂)
c) Carbon dioxide (CO₂)
d) Which of the three molecules listed above contains a double bond?
Answer:
a) Bromine gas (Br₂) :

b) Calcium chloride (CaCl₂)

c) Carbon dioxide (CO₂) :

d) CO₂, contains double bond in above list. Its structure is like this : O = C = O.

Question 14.
Two chemical reactions are described below. (AS5)
♦ Nitrogen and hydrogen react to form ammonia (NH₃).
♦ Carbon and hydrogen bond to form a molecule of methane (CH₄).
For each reaction give :
a) The valency of each of the atoms involved in the reaction.
b) The Lewis structure of the product that is formed.
Answer:
a) ♦ Nitrogen and hydrogen react to form ammonia (NH₃):
i) The valency of nitrogen is 3 and hydrogen is 1.
ii) The chemical formula of the product is NH₃

♦ Carbon and hydrogen bond to form a molecule of methane (CH₄):
i) The valency of carbon is 4 and hydrogen is 1.
ii) The chemical formula of the product is CH₄.

b) ♦ The Lewis structure of the product that is formed (: NH₃)

♦ The Lewis structure of the product that is formed (CH₄)

Question 15.
How does Lewis dot structure help in understanding bond formation between atoms? (AS6)
(OR)
What is the use of Lewis dot structure in bond formation? Explain.
Answer:

1. Only the outermost electrons of an atom take part in chemical bonding.
2. They are known as valence electrons.
3. The valence electrons in an atom are represented by putting dots (•) on the symbol of the element, one dot for each valence electron.
4. For example, sodium atom has 1 valence electron in its outermost shell, so we put 1 dot with the symbol of sodium and write Na• for it.
5. Sodium atom loses this 1 electron to form sodium ion.
6. By knowing the valence electrons of two different atoms by Lewis dot structure, we can understand which type of bond is going to establish between them and forms corresponding molecule.

Question 16.
What is octet rule? How do you appreciate role of the ‘octet rule’ in explaining the chemical properties of elements? (AS6)
(OR)
Which rule decides whether given element is chemically stable or not? Appreciate that rule.
Answer:
Octet rule decides whether given element is stable or not.
Octet rule :

• ‘The atoms of elements tend to undergo chemical changes that help to leave their atoms with eight outer shell electrons.”
• It was found that the elements which participate in chemical reaction get octet (or) ns2 np6 configuration similar to that of noble gas elements.

Role of octet in chemical properties of elements :

1. Except He remaining inert gas elements have 8 electrons in their outermost orbit. Since these elements are having stable octet configuration in their outermost orbit, they are very stable.
2. They do not allow the outermost electrons to take part in chemical reactions.
3. So by having octet configuration for these elements we can conclude these are chemically inertial.
4. If any group of elements (take halogens) which contain 7 electrons in their outermost orbit, they require only 1 e^– to get octet configuration.
5. So they try to participate in chemical reaction to get that 1 difference electron for octet configuration.
6. Similarly, Na contains 2, 8, 1 as its electronic configuration.
7. So it loses le^– from its outermost shell; it should have 8e^– in its outer shell and get the octet configuration.
8. Thus the octet rule helps in explaining the chemical properties of elements.

Question 17.
Explain the formation of the following molecules using valence bond theory.
a) N₂ molecule
b) O₂ molecule
(OR)
Write the formation of double bond and triple bond according to valence bond theory.
(OR)
Who proposed Valence Bond Theory? Explain the formation of N₂ molecule by using this theory.
Answer:
Linus Pauling was proposed valence bond theory.
Formation of N₂ molecule :

1. Electronic configuration of Nitrogen is 1s² 2s² 2p_x¹ 2p_y¹ 2p_z¹.
2. Suppose that p_x orbital of one Nitrogen atom overlaps the p_x orbital of other ‘N’ atom giving σ p_x – p_x bond along the inter nuclear axis.
3. The p_y and p_z orbitals of one ‘N’ atom overlaps with the p_y and p_z orbital of other ‘N’ atom laterally giving π p_y – p_y and π p_z – p_z bonds.
4. Therefore, N₂ molecule has a triple bond between two Nitrogen atoms.

Formation of O₂ molecule :

1. Electronic configuration of ‘O’ is 1s² 2s² 2p_x² 2p_y¹ 2p_z¹.
2. If the P_y orbital of one ‘O’ atom overlaps the p_y orbital of other ‘O’ atom along inter- nuclear axis, a σ p_y – p_y bond is formed.
3. p_z orbital of oxygen atom overlaps laterally, perpendicular to inter nuclear axis giving a π p_y – p_z bond.
4. So O₂ molecule has a double bond between the two oxygen atoms.

Question 18.
What is hybridisation? Explain the formation of the following molecules using hybridisation.
a) BeCl₂
b) BF₃
Explain the formation of sp and sp² hybridisation using examples.
(OR)
What is the name given to inter mixing of atomic orbitals to form new orbitals. Explain the formation of following molecules by using that process,
a) BeCl₂
b) BF₃
Answer:
This process is called hybridisation.
Hybridisation :
It is a phenomenon of inter mixing of atomic orbitals of almost equal energy which are present in the outer shells of the atom and their reshuffling or redistribution into the same number of orbitals but with equal properties like energy and shape.

a) Formation of BeCl₂ (Beryllium chloride) molecule :

1. ₄Be has electronic configuration 1s² 2s².
2. It has no unpaired electrons.
3. It is expected not to form covalent bonds, but informs two covalent bonds one each with two chlorine atoms. „
4. To explain this, an excited state is suggested for Beryllium in which an electron from ‘2s’ shifts to 2p_x level.
5. Electronic configuration of ₄Be is 1s² 2s¹ 2p_x¹].
6. Electronic configuration of ₁₇Cl is 1s² 2s² 2p⁶ 3s² 3p_x² 3p_y² 3p_z¹.
7. If Be forms two covalent bonds with two chlorine atoms, one bond should be σ 2s-3p due to the overlap of ‘2s’ orbital of Be, the ‘3p_z‘ orbital of one chlorine atom.
8. The other bond should be σ 2p-3p due to the overlap of ‘2p_x’ orbital of Be atom the 3p orbital of the other chlorine atom.
9. As the orbitals overlapping are different, the bond strengths of two Be-Cl must be different.
10. But, both bonds are of same strength and Cl\(\hat{\mathrm{Be}}\) Cl is 180°.

The Hybridisation of BeCl₂ can be explained in this way also :
a) Be atom in its excited state allows its 2s orbital and 2p_x orbital which contain unpaired electrons to intermix and redistribute to two identical orbitals.
b) As per Hund’s rule each orbital gets one electron.
c) The new orbitals based on the types of orbitals that have undergone hybridisation are called sp orbitals.
d) The two sp orbitals of Be get separated by 180°.
e) Now each chlorine atom comes with its 3p_z¹ orbital and overlaps it the sp orbitals of Be forming two identical Be-Cl bonds (σ sp-p bonds).
Cl\(\hat{\mathrm{Be}}\) Cl = 180°.

f) Both the bonds are of same strength.

b) Formation of BF₃ molecule :

1. ₅B has electronic configuration 1s² 2s² 2pxh
2. The excited electronic configuration of ₅B is 1s² 2s¹ 2p_x¹ 2p_y¹
3. As it forms three identical B-F bonds in BF₃.
4. It is suggested that excited ‘B’ atom undergoes hybridisation.
5. There is an intermixing of 2s, 2p_x, 2p_y orbitals and their redistribution into three identical orbitals called sp² hybrid orbitals.
6. For three sp² orbitals to get separated to have minimum repulsion the angle between any two orbitals is 120° at the central atom and each sp² orbital gets one election.
7. Now three fluorine atoms overlap their 2p_z orbitals containing unpaired electrons (F₉ 1s² 2s² 2p_x² 2p_y² 2p_z¹) the three sp² orbitals of ‘B’ that contain unpaired electrons to form three σsp²-p bonds.

Fill in the Blanks

1. Electrons in the outermost orbit are called …………………… .
2. Except …………………… gas all other noble gases have octet in their valence shell.
3. Covalency of elements explains about member of …………………… formed by the atom.
4. Valence bond theory was proposed by …………………… .
5. In …………………… bonding the valence electrons are shared among all the atoms of the metallic elements.
Answer:

1. valence electrons
2. Helium
3. covalent bonds
4. Linus Pauling
5. covalent

Multiple Choice Questions

1. Which of the following elements is electronegative?
A) Sodium
B) Oxygen
C) Magnesium
D) Calcium
Answer:
B) Oxygen

2. An element ₁₁X²³ forms an ionic compound with another element ‘Y’. Then the charge on the ion formed by X is
A) +1
B) +2
C) -l
D) – 2
Answer:
A) +1

3. An element ‘A’ forms a chloride ACl₄. The number of electrons in the valence shell of ‘A’
A) 1
B) 2
C) 3
D) 4
Answer:
D) 4

10th Class Chemistry 10th Lesson Chemical Bonding InText Questions and Answers

10th Class Chemistry Textbook Page No. 153

Question 1.
How do elements usually exist?
Answer:
They may exist as a single atom or as a group of atoms.

Question 2.
Do atoms exist as a single atom or as a group of atoms?
Answer:
Atoms exist as a single atom, sometimes as a group of atoms also.

Question 3.
Are there elements which exist as atoms?
Answer:
Yes. There are elements which exist as atoms.

Question 4.
Why do some elements exist as molecules and some as atoms?
Answer:
By following different laws of chemical combination the chemical compounds take place as a result of combination of atoms of various elements in different ways.

Question 5.
Why do some elements and compounds react vigorously while others are inert?
Answer:
1) Number of electrons in their outermost shell.
2) Bond strength between the atoms in compound.

Question 6.
Why is the chemical formula for water H₂O and for sodium chloride NaCl, why not HO₂ and NaCl₂?
Answee:
Valencies of the atoms participating in the molecules.

Question 7.
Why do some atoms combine dille tl do not?
Answer:
1) Atoms which have 8e“ in their outer shell will not combine.
2) Atoms which have more than or less than 8e“ in their outer shell will combine.

Question 8.
Are elements and compounds simply made up of separate atoms Individually arranged?
Answer:
No. Elements and compounds are not simply made up of separate atoms individually arranged.

Question 9.
Is there any attraction between atoms?
Answer:
Yes. There is some attraction betwen atoms.

Question 10.
What is that holding them together?
Answer:
Force of attraction between them.

10th Class Chemistry Textbook Page No. 155

Question 11.
Why is there absorption of energy in certain chemical reactions and release of energy in other reactions?
Answer:’
Because of bond energy between the atoms in a molecule.

Question 12.
Where does the absorbed energy go?
Answer:
For breaking chemical bonds between atoms in a molecule.

Question 13.
Is there any relation to energy and bond formation between atoms?
Answer:
Yes. There is some relation to energy and bond formation between atoms.

Question 14.
What could be the reason for the change in reactivity of elements?
Answer:
Number of electrons in their outermost orbit.

Question 15.
What could be the reason for this?
Answer:
They have 8 (e^–) electrons in their outermost orbit.

10th Class Chemistry Textbook Page No. 157

Question 16.
What did you notice in Lewis dot structure of noble gases and electronic configurations of the atoms of these elements shown in table – 1?
Answer:
Except He remaining Ne, Ar, Kr have 8 electrons in their outermost orbit.

10th Class Chemistry Textbook Page No. 158

Question 17.
What have you observed from the above conclusions about the main groups?
Answer:

1. Number of gained electrons of non-metals in their valency.
2. Number of lost electrons of metals in their valency.

Question 18.
Why do atoms of elements try to combine and form molecules?
Answer:
To attain stable electronic configuration.

10th Class Chemistry Textbook Page No. 159

Question 19.
Is it accidental that IA to VIIA main group elements during chemical reactions get eight electrons in the outermost shells of their ions, similar to noble gas atoms?
Answer:
No, it cannot be simply accidental.

Question 20.
Explain the formation of ionic compounds NaCl, MgCl₂, Na₂O and AlCl₃ through Lewis electron dot symbols (formulae).
Answer:
1) Lewis electron dot symbol for NaCl:

Formation of sodium chloride (NaCl) :
Sodium chloride is formed from the elements sodium and chlorine. It can be explained as follows.
Na_(s) + ½Cl_2(g) → NaCl₂

Cation formation :
When sodium (Na) atom loses one electron to get octet electron configuration it forms a cation (Na+) and gets electron configuration that of Neon (Ne) atom.

Anion formation :
Chlorine has shortage of one electron to get octet in its valence shell. So it gains the electron from Na atom to form anion and gets electron configuration as that of argon (Ar).

Formation of the compound NaCl from its ions :
Transfer of electrons between ‘Na’ and ‘Cl’ atoms, results in the formation of ‘Na⁺‘ and ‘Cl^–‘ ions. These oppositely charged ions get attracted towards each other due to electrostatic forces and form the compound sodium chloride (NaCl).
Na⁺_(g) + Cl^–_(g) → Na⁺Cl^–_(s) or NaCl

2) Lewis electron dot symbol for MgCl₂:
MgCl₂

Formation of magnesium chloride (MgCl₂):
Magnesium chloride is formed from the elements magnesium and chlorine. The bond formation MgCl₂ in brief using chemical equation is as follows :
Mg_(s) + Cl_2(g) → MgCl_2(g)
Cation formation:

Anion formation :

The compound MgCl₂ formation from its ions :
Mg²⁺ gets ‘Ne’ configuration and
Each Cl^– gets ‘Ar’ configuration
Mg²⁺_(g) + 2 Cl^–_(g) → MgCl_2(s)
One ‘Mg’ atom transfers two electrons one each to two ‘Cl’ atoms and so formed Mg²⁺ and 2Cl^– attract to form MgCl₂.

3) Lewis electron dot symbol for (Na₂O) :

Formation of di sodium monoxide (Na₂O):
Di sodium monoxide formation can be explained as follows:
Cation formation (Na⁺ formation):

Two ‘Na’ atoms transfer one electron each to one oxygen atom to form 2 Na⁺ and O^2-
Each Na⁺ gets ‘Ne’ configuration and O^2- gets ‘Ne’ configuration.
These ions (2Na⁺ and O^2-) attract to form Na₂O.

4) Lewis electron dot symbol for (AlCl₃):

Formation of aluminium chloride (AlCl₃):
Aluminium chloride formation can be explained as follows:
Formation of aluminium ion (Al³⁺), the cation:

Each aluminium atom loses three electrons and three chlorine atoms gain them, one electron each.
The compound AlCl₃ is formed from its component ions by the electrostatic forces of attractions.
Al³⁺_(g) + 3 Cl^–_(g) → AlCl_3(s)

10th Class Chemistry Textbook Page No. 163

Question 21.
How do cations and anions of an ionic compound exist in its solid state?
Answer:
Ionic compounds exist in crystalline state.

Question 22.
Do you think that pairs of Na⁺ Cl^– as units would be present in the solid crystal?
Answer:
Yes. I think that pairs of Na⁺ Cl^– as units would be present in the solid crystal.

10th Class Chemistry Textbook Page No. 164

Question 23.
Can you explain the reasons for all these?
Answer:
Ionic bond is formed between atoms of elements with electronegativity, difference equal to or greater than 1.9.

10th Class Chemistry Textbook Page No. 165

Question 24.
Can you say what type of bond exists between atoms of nitrogen molecule?
Answer:
Triple bond exists between atoms of nitrogen molecule.

10th Class Chemistry Textbook Page No. 168

Question 25.
What do you understand from bond lengths and bond energies?
Answer:
Bond lengths and bond energies are not same when the atoms that form the bond are different.

Question 26.
Are the values not different for the bonds between different types of atoms?
Answer:
Yes. The values are not different for the bonds between different types of atoms.

10th Class Chemistry Textbook Page No. 170

Question 27.
What is the bond angle in a molecule?
Answer:
It is the angle subtended by two imaginary lines that pass from the nuclei of two atoms which form the covalent bonds with the central atom through the nucleus of the central atom at the central atom.

10th Class Chemistry Textbook Page No. 172

Question 28.
How is MCI molecule formed?
Answer:
The ‘1s’ orbital of ‘H’ atom containing unpaired electron overlaps the ‘3p’ orbital of chlorine atom containing unpaired electron of opposite spin.

10th Class Chemistry 10th Lesson Chemical Bonding Activities

Activity – 1

1. Write the Lewis structures of the given elements in the table. Also, consult the periodic table and fill in the group number of the element.
Answer:

AP State Board Syllabus AP SSC 10th Class Physics Solutions Chapter 12 Electromagnetism Textbook Questions and Answers.

AP State Syllabus SSC 10th Class Physics Solutions 12th Lesson Electromagnetism

10th Class Physics 12th Lesson Electromagnetism Textbook Questions and Answers

Review of Your Previous Knowledge

Question 1.
How do electric appliances work?
Answer:
Electrical appliances work due to the electric force. Electrical force works in displacing the charges. Electric force is independent of the state of rest or the motion of the charged particle. Electric motor, washing machine are some of the examples of electric appliances.

Question 2.
How do electromagnets work?
Answer:
An electromagnet acquires the magnetic properties only when electric current is passed through the solenoid. Once the current is switched off, it almost loses its magnetic properties as retentivity of soft iron is very low. The strength of the electromagnet depends upon number of turns per unit length of the solenoid and the current through the solenoid.

Question 3.
Is there any relation between electricity and magnetism?
Answer:
The first evidence that there exists such a relationship between electricity and magnetism was observed by Oersted. When current carrying conductor was parallel to the axis of the needle, and the needle was deflected. This was much against his expectations. On reversing the direction of the current the needle moved in opposite direction.

Question 4.
Can we produce magnetism from electricity?
Answer:
We can produce magnetism from electronic current. Ampere with his Ampere’s swimming rule explained the direction of electric current and the deflection of magnetic needle.

Improve Your Learning

Question 1.
Are the magnetic field lines closed? Explain. (AS1)
Answer:

• Magnetic field lines are closed.
• If we observe the field lines formed by a current carrying straight wire, circular field lines are formed. They are closed circles.
• If we observe the field lines by a current carrying solenoid the field lines out side the solenoid are continuous with those inside.
• Thus the magnetic field lines are closed loops.

Question 2.
See figure, magnetic lines are shown. What is the direction of the current flowing through the wire? (AS1)

Answer:
If field lines are in anti-clockwise direction as shown in the diagram, the direction of current is vertically upwards. This can be demonstrated with right hand thumb rule.

Question 3.
A bar magnet with north pole facing towards a coil moves as shown in figure. What happens to the magnetic flux passing through the coil? (AS1)

(OR)
Why would induced current be generated in the coil when a north pole of a bar magnet pushed into it ?
Answer:
If north pole of the magnet moves towards the coil, there is a continuous change of magnetic flux linked with closed coil, then current is generated in the coil.

Question 4.
A coil is kept perpendicular to page. At P, current flows into the page and at Q it comes out of the page as shown in figure. What is the direction of magnetic field due to the coil? (AS1)

Answer:
At the top, anti-clockwise direction.
At the bottom, clockwise direction.
Try This:

Take a test tube and wound minimum 50 turns of 24 guage insulated copper wire with 2cms length at the centre of test tube as shown in figure, ‘l Now solenoid is ready. Take 3cms length of iron nail and make it floats on water with appropriate foam (thermocol) on the water. Now connect the j two ends of solenoid two 3-6 volts battery eliminator and switch on the eliminator. You can observe the motion of the nail towards the solenoid. (If not move decrease the water level or increase the potential).
Try to explain motion of the nail into the water using solenoid concept.

Question 5.
The direction of current flowing in a coil is shown in the figure. What type of magnetic pole is formed at the face that has flow of current as shown in the figure? (AS1)

Answer:
North. Since the current in the coil flows in anti-clockwise direction, north pole is formed at the face we are watching. 

Question 6.
Why does the picture appear distorted when a bar magnet is brought close to the screen of a television? Explain. (AS1)
(OR)
Explain magnetic force on moving charge and current carrying wire.
(OR)
What happens when you bring a bar magnet near a picture of TV screen ? What inference do you conclude from this activity?
Answer:
This is due to the fact that magnetic field exerts a force on the moving charge.

TV screen Activity :

• Take a bar magnet and bring it near the TV screen.
• Then the picture on the screen is distorted.
• Here the distortion is due to the motion of the electrons reaching the screen are affected by the magnetic field.
• Now move the bar magnet away from the screen.
• Then the picture on the screen stabilizes.
• This must be due to the fact that the magnetic field exerts a force on the moving charges. This force is called magnetic force.
• The magnitude of the force is F = Bqv where B is magnetic induction, ‘q’ is the charge and v is the velocity of the charged particle.

Question 7.
Symbol ‘X’ indicates the direction of a magnetic held into the page. A straight long wire carrying current along its length is kept perpendicular to the magnetic field. What is the magnitude of force experienced by the wire? In what direction does it act? (AS1)

Answer:
1) Magnetic force (F) experienced by the wire with the magnitude of ILB :
Here I = Current, L = Length of the wire B = Magnetic field

2) Direction of the magnetic force (F) :

1) The direction of force can be find by using Right hand rule.
2) Fore finger → i (North)
Middle finger → B (into the page)
Thumb → F (Towards west parallel to the paper)

Question 8.
Explain the working of electric motor with a neat diagram. (AS1)
(OR)
Which device converts electrical energy into mechanical energy? Explain the working of that device with a neat diagram.
Answer:
Electric motor converts electrical energy into mechanical energy.
Electric motor:
It is a device which converts electrical energy into mechanical energy.

Principle :
It is based on the principle that a current carrying conductor placed perpendicular to the magnetic field experiences a force.

Construction :
a) Armature coil:
It contains a single loop of an insulated copper wire in the form of a rectangle.

b) Strong magnetic field :
Armature coil is placed between two permanent poles (N & S) of a strong magnet.

c) Slip-ring Commutator:
It consists of two halves (C₁ and C₂) of a metallic ring. The two ends of the armature coil are connected to these two halves of the ring. Commutator reverses the direction of current in the armature coil.

d) Brushes:
Two carbon brushes B₁ and B₂ press against the commutator. These brushes act as the contact between the commutator and terminals of the battery.

e) Battery :
A battery is connected across the carbon brushes. The battery supplies the current to the armature coil.

Working and Theory :

1. When current flows through the coil, AB and CD experience magnetic force.
2. In the arm, AB of the coil experiences a force in one direction, similarly, in CD it experiences in opposite direction.
3. These two equal and opposite forces constitute a couple; which rotates the coil.
4. At this position, the supply of current to the coil is cut off because contacts of commutator and brushes break.
5. Hence no force acts on the arms of the coil.
6. The coil will not come to rest because of rotational inertia of motion, till the commutator again comes in contact with the brushes B₁ and B₂.
7. Now the direction of the current in the arms AB and CD is reversed.
8. Then the couple again rotates in opposite direction.
9. The coil of DC motor continues to rotate in the same direction. Hence electrical energy is converted into mechanical energy.
10. The speed of rotation of the motor depends on
    a) current through the armature
    b) number of turns of the coil
    c) area of the coil
    d) magnetic induction.

Question 9.
Derive Faraday’slaw of induction from law of conservation of energy. (AS1)
Answer:
Faraday’s law :
Whenever there is a continuous change in magnetic flux linked with coil closed the current is generated in the coil.

• Consider a pair of parallel bare conductors which are separated by 7′ meters.
• They are placed in uniform magnetic field of induction ‘B’ supplied by ‘N’ and ‘S’ poles of the magnet.
• A galvanometer is connected to the ends of the parallel conductors.
• We can close the circuit by touching the parallel conductor with another bare conductor which is taken in our hand.
• If we move our hand to the left, the galvanometer needle will deflect in one direction.
• If we move our hand to the right, the needle in the galvanometer moves in opposite direction.
• A current will be set up in the circuit only when there is an EMF in the circuit. Let EMF be ‘ε’.
• The principle of conservation energy tells us that this electric energy must come from the work that we have done in moving the cross wire.

Question 10.
The value of magnetic field induction which is uniform is 2T. What is the flux passing through a surface of area 1.5 m2 perpendicular to the field? (AS1)
Answer:
B = 2T ; Φ == ? ; A = 1.5 m²
We know B = \(\frac{\phi}{\mathrm{A}}\)
or Φ = BA = 2 × 1.5 =3 Webers

Question 11.
An 8N force acts on a rectangular conductor 20 cm long placed perpendicular to a magnetic field. Determine the magnetic field induction if the current in the conductor is 40 A. (AS1)
Answer:
F = 8N ; l = 20 cm or 20 × 10^-2 m ; B = ? ; i = 40 Amp

Question 12.
Explain with the help of two activities that current carrying wire produces magne tic field. (AS1)
(OR)
How can you verify that a current carrying wire produces a magnetic field with the help of experiment?
Answer:
Activity – 1

• Take a thermocole sheet and fix two thin sticks ol height 1cm.
• Join the two sticks with the help of copper wire.
• Take a battery, tap key and connect them in series with the copper wire which is thin.
• Keep a marine compass needle beneath the wire.
• If you press the tap key, current flows in the copper wire.
• Immediately the magnetic needle gets deflected.
• This indicates that the magnetic field is increased when current flows through the conductor.

Activity – 2

• Take a wooden plank and make a hole.
• Place the plank on the table.
• Place the retort stand on it.
• Pass copper wire through the hole.
• Connect the two ends of the wire with battery through switch.
• Place some compass needle around the hole.
• When the current flows the magnetic needle deflects.
• We can verify this by changing the direction of current.
• So we can conclude the magnetic field surrounds a current carrying conductor.

Question 13.
How do you verify experimentally that the current carrying conductor experiences a force when it is kept in magnetic field? (AS1)
Answer:

1. A copper wire is passed through splits of wooden sticks.
2. Connect the wire to 3 volts battery.
3. Close the switch of the battery and pass the current.
4. Bring the horse-shoe magnet near the wire.
5. Then a force is experienced on the wire.
6. Reverse the polarities of the magnet, then the direction of the force is also reversed.
7. The right hand rule helps the direction of flow of current and the direction of current.

Question 14.
Explain Faraday’s law of induction with the help of an activity. (AS1)
(OR)
Write an activity which proves changing magnetic flux produces induced current in the circuit.
Answer:

• Connect the terminals of a coil to a sensitive ammeter.
• Push a bar magnet towards the coil, with its north pole facing the coil, the needle in the galvanometer deflects.
• It shows that a current is set up in the coil.
• The galvanometer does not deflect if the magnet is at rest.
• If the magnet is moved away from the coil, the needle in the galvanometer again deflects in opposite direction.
• Further this experiment enables us to understand that the relative motion of the magnet and coil set up a current in the coil. It makes no difference whether the magnet is moved towards the coil. This is one form of Faraday’s law.

Question 15.
Explain the working of AC electric generator with a neat diagram. (AS1)
(OR)
Which device converts mechanical energy into electrical energy? Explain the working of that device with a neat diagram.
Answer:
Generator converts mechanical energy into electrical energy.

• As armature is rotated about an axis, the magnetic flux linked with armature changes. Therefore, an induced current is produced in the armature.
• If the armature rotates in anti-clockwise direction, from Flemming’s right hand rule the direction of current and deflection of the coil are noted.
• Alter armature has turned through 180°, it occupies another position.
• By applying Flemming’s right hand rule we can find the direction of current and deflection of the needle.
• Hence we can conclude the induced current is alternating in nature.

Question 16.
Explain the working of DC generator with a neat diagram. (AS1)
Answer:

• The principle and working of D.C generator is same as that of AC generator except that in place of slip – rings as sliding contacts, we have a slip-ring or a commutator.
• In a slip ring, there are two half rings.
• The ends of armature coil are connected to these rings and these rings rotate the armature.
• By using slip-ring, the direction of induced current does not change in the external circuit throughout the complete rotation of the armature. In other words, the current in the external circuit always flows in the same direction. Hence the induced current is unidirectional.

Question 17.
Rajkumar said to you that the magnetic field lines are open and they start at north pole of bar magnet and end at south pole. What questions do you ask Rajkumar to correct him by saying “field lines are closed”? (AS2)
Answer:

• If the magnetic field lines start at north pole and end at south pole, where do the lines go from south pole?
• What is happening within the bar magnet?
• Are the magnetic field lines passing through bar magnet?
• What is the direction of magnetic field lines inside the bar magnet? (Recall the solenoid activity).
• Can you say now, that the magnetic field lines are open?

Question 18.
As shown in figure, both coil and bar magnet move in the same direction. Your friend is arguing that there is no change in flux. Do you agree with his statement? If not, what doubts do you have? Frame questions about the doubts you have regarding change in flux. (AS2)

Answer:

• What happens if both magnet and coil move in same direction?
• What happens if both magnet and coil move in opposite direction?
• What is the direction of the current in the coil?
• If both move in same direction, is there any linkage of flux with the coil?
• When ‘N’ pole is moved towards the coil what is the direction of current?
• If magnet is reversed, what is the direction of current in the coil?

Question 19.
What experiment do you suggest to understand Faraday’s law? What items are required? What suggestions do you give to get good results of the experiment? Give precautions also. (AS3)
Answer:
Aim :
To understand Faraday’s law of induction.

Materials required :
A coil of copper wire, a bar magnet, Galvanometer, etc.

Procedure :

1. Connect the terminal of a coil to a sensitive galvanometer as shown in the figure.
2. Normally, we would not expect any deflections of needle in the galvanometer because there is to be no electromotive force in this circuit.
3. Now if we push a bar magnet towards the coil, with its north pole facing the coil, we observe the needle in the galvanometer deflects, showing that a current is set up in the coil.
4. The galvanometer does not deflect if the magnet is at rest.
5. If the magnet is moved away from the coil, the needle in the galvanometer again deflects, but in the opposite direction, which means that a current is set up in the coil in the opposite direction.
6. If we use the end of south pole of a magnet instead of north pole in the above activity, the deflections are exactly reversed.
7. This experiment proves “whenever there is a continuous change of magnetic flux linked with a closed coil, a current is generated in the coil”.

Precautions :

1. The coil should be kept on an insulating surface.
2. Bar magnet should be of good magnetic moment.
3. The centre of the galvanometer scale must be zero.
4. The deflections in the galvanometer must be observed while introducing the bar magnet into the coil and also while withdrawing it.

Question 20.
How can you verify that a current carrying wire produces a magnetic field with the help of an experiment? (AS3)
Answer:
Experiment:

• Take a thermocole sheet and fix two thin wooden sticks of height 1cm.
• These sticks are joined with the help of a copper wire.
• Connect battery and tap key to this copper wire.
• Place a magnetic compass beneath the wire.
• Now press the tap key and allow the current through the wire. It is observed that magnetic needle deflects.
• If you change the direction of the current, the direction of deflection of needle also changes.
• So we can say current carrying conductor produces magnetic field.

Question 21.
Collect information about generation of current by using Faraday’s law. (AS4)
Answer:
Faraday’s law is useful in generation of current.

1. According to this law, the change in magnetic flux induces EMF in the coil.
2. Fie also proposed electromagnetic induction.
3. Electromagnetic induction is a base for generator, which produces electric current.
4. Transformer also works on the principle of electromagnetic induction, which is helpful in transmission of electricity.
5. Hence Faraday’s law is used in the generation and transmission of current.

Question 22.
Collect information about material required and procedure of making a simple electric motor from internet and make a simple ntotor on your own. (AS4)
Answer:
Aim :
Preparation of a simple electric motor.

Material requried :
A wire of nearly 15 cm, 1.5v Battery, Iron nail, strong magnet, paper clip.

Procedure:

1. Attach the magnet to the head of the iron nail.
2. Attach a paper clip to the open end of the magnet.
3. Now attach the other end of the nail (Free end) to the cap (positive terminal) of the battery.
4. Now connect the negative terminal of the battery and the head of the iron nail through a wire.
5. We observe that the paper clip rotates.

Another model:
Materials required :
1.5 m enamelled copper wire (about 25 gauge), 2 safety pins,
1.5 v battery, magnets, rubber bands or bands cut from cycle tube.

Procedure :

1. Wind copper wire on the battery nearly 10 – 15 turns to make a coil.
2. Remove the coil and fix the ends as shown in the figure.
3. Scrape the insulation com¬pletely on one end of the coil.
4. Scrape the insulation on top, left and right of the other end. The bottom should be insulated.
5. Now complete the electric mo¬tor as shown in the figure. “5

Question 23.
Collect information of experiments done by Faraday. (AS4)
Answer:
Experiment – 1

1. Connect the terminals of a coil to a sensitive galvanometer as shown in the figure.
2. Normally, we would not expect any deflection of needle in the galvanometer because there is no EMF in the circuit.
3. Now, if we push a bar magnet towards the coil, with its north pole facing the coil, the needle in the galvanometer deflects, showing that a current has been set up in the coil, the galvanometer does not deflect if the magnet is at rest.
4. If the magnet is moved away from the coil, the needle in the galvanometer again deflects, but in the opposite direction, which means that a current is set up in the coil in the opposite direction.
5. If we use the end of south pole of a magnet instead of north pole, the results i.e., the deflections in galvanometer are exactly opposite to the previous one.
6. This activity proves that the change in magnetic flux linked with a closed coil, produces current.
7. From this Faraday’s law of induction can be stated as “whenever there is a continuous change of magnetic flux linked with a closed coil, a current is generated in the coil”. This induced EMF is equal to the rate of change of magnetic flux passing through it.

Experiment – 2

1. Prepare a coil of copper wire C₁ and connect the two ends of the coil to a galvanometer.
2. Prepare another coil of copper wire similar to C₂ and connect the two ends of the coil to a battery via switch.
3. Now arrange the two coils C₁ and C₂ nearby as shown in the figure.
4. Now switch on the coil C₂. We observe a deflection in the galvanometer connected to the coil C₁.
5. The steady current in C₂ produces steady magnetic field. As coil C₂ is moved towards the coil C₁ the galvanometer shows a deflection.
6. This indicates that electric current is induced in coil C₁.
7. When C₂ is moved away, the galvanometer shows a deflection again, but this time in the opposite direction.
8. The deflection lasts as long as coil C₂ is in motion.
9. When C₂ is fixed and C₁ is moved, the same effects are observed.
10. This shows the induced EMF due to relative motion between two coils.

Question 24.
Draw a neat diagram of electric motor. Name the parts. (AS5)
Answer:

Question 25.
Draw a neat diagram of an AC generator. (AS5)
(OR)
Draw the diagram of electric generator and label its parts. A.
Answer:

Question 26.
How do you appreciate the Faraday’s law, which is the consequence of conservation of energy? (AS6)
Answer:

• Law of conservation of energy says energy neither be created nor be destroyed, but can be converted from one form to another.
• Faraday’s law says whenever there is a continuous change of magnetic flux linked with a closed coil, a current is generated in the coil. This induced EMF is equal to the rate of change of magnetic flux passing through it.
• We have to do some work to move the magnet through a coil. This work produces energy.
• This energy is converted into electrical energy in the coil.
• In this way conservation of energy takes place in electromagnetic induction.

Question 27.
How do you appreciate the relation between magnetic field and electricity that changed the lifestyle of mankind? (AS6)
Answer:

• Changing life style of mankind is a result of many inventions, utilising a lot of scientific principles.
• Scientists all ways going on searching for new principles and new applications to make our life more comfortable.
• If you consider electricity, right from amber stone to nuclear power, so many changes have been incorporated.
• The idea of Oersted and Faraday that current carrying wire produces electricity and electromagnetic induction, enable us to use electric motors, generators, fans, mixers, grinders, induction stoves, etc.
• All these appliances makes our life more comfortable. Hence Faraday and Oersted rendered a lot of servies in this field.
• Hence, I appreciate the relation between magnetic field and electricity that changed the life style of mankind.
  So if current is more, induction is also more.

Question 28.
Give a few applications of Faraday’s law of induction in daily life. (AS7)
Answer:
Applications:
The daily life applications of Faraday’s law of induction are

1. Generation of electricity
2. Transmission of electricity
3. Metal detectors in security checking
4. The tape recorder
5. Use of ATM cards
6. Induction stoves
7. Transformers
8. Induction coils (spark plugs in automobiles)
9. Break system in railway wheels
10. AC and DC generators
11. Windmills, etc.

Question 29.
Which of the various methods of current generation protects the nature well? Give examples to support your answer. (AS7)
Answer:
Windmill :

• Electricity is produced when an armature of a generator rotates between two poles of a strong magnet.
• Whereas when wind falls on the wheel of a windmill, it rotates. So the armature of the generator rotates between two poles of a magnet along with the rotation of the wheel of the windmill.
• Thus electric current is produced.
• This is how, KE of the wind is converted into electric energy.

Advantages :
Wind energy produces no smoke and no harmful gases. So this form of energy is pollution free or environment-friendly.

Fill in The Blanks

1. The SI unit of magnetic field induction is ………………….
2. Magnetic flux is the product of magnetic field induction and …………………
3. The charge is moving along the direction of magnetic field. Then force acting on it is ………………..
4. A current carrying wire of length L is placed perpendicular to a uniform magnetic field B. Then the force acting on the wire with current I is ……………..
5. Faraday’s law of induction is the consequence of …………………
Answer:

1. weber/m² (or) Tesla
2. area
3. zero
4. ILB
5. Law of conservation of energy

Multiple Choice Questions

1. Which converts electrical energy into mechanical energy?
A) motor
B) battery
C) generator
D) switch
Answer:
A) motor

2. Waich converts mechanical energy into electrical energy?
(OR)
The device used to convert mechanical energy into electrical energy among the following is
A) motor
B) battery
C) generator
D) switch
Answer:
C) generator

3. The magnetic force on a current carrying wire placed in uniform magnetic field if the wire is oriented perpendicular to magnetic field, is
A) 0
B) ILB
C) 2ILB
D) ILB/2
Answer:
B) ILB

10th Class Physics 12th Lesson Electromagnetism InText Questions and Answers

10th Class Physics Textbook Page No. 221

Question 1.
Why does the needle get deflected by the magnet?
Answer:
Because of strength of the magnetic field of the magnet, the needle gets deflected since it is in the field.

10th Class Physics Textbook Page No. 213

Question 2.
How can we find the strength of the field and direction of the field?
Answer:
We can find the strength of the field with magnetic flux and the direction of the field from the tangent drawn to the line of force.

10th Class Physics Textbook Page No. 214

Question 3.
Can we give certain values to magnitude of the field at every point in the magnetic field?
Answer:
In uniform magnetic field it is same whereas in non-uniform magnetic field it is different.

10th Class Physics Textbook Page No. 215

Question 4.
What is the flux through unit area perpendicular to the field?
Answer:
Flux density or magnetic induction.

Question 5.
Can we generalize the formula of flux for any orientation of the plane taken in the field?
Answer:
Yes, Φ = BA cos θ

Question 6.
What is the flux through the plane taken parallel to the field?
Answer:
Magnetic flux (or) Magnetic field.

Question 7.
What is the use of introducing the ideas of magnetic flux and magnetic flux density?
Answer:
Magnetic flux and flux density help in understanding the concept of electromagnetic induction and relation between electricity and magnetism.

Question 8.
Are there any sources of magnetic field other than magnets?
Answer:
Current carrying straight wires and loops act as sources of magnetic filed.

Question 9.
Do you know how old electric calling bells work?
Answer:
Yes. They work on the principle of magnetic effect of electric currents.

10th Class Physics Textbook Page No. 218

Question 10.
What happens when a current carrying wire is kept in a magnetic field?
Answer:

• Magnetic field applies force on current carrying wire.
• So it gets deflected and the direction of deflection is given by right hand rule.
• Or there will be no force acting on the wire when wire is in the direction of the field.

10th Class Physics Textbook Page No. 219

Question 11.
Do you feel any sensation on your skin?
Answer:
Yes. The hair on my skin rises up when I stand near TV screen.

Question 12.
What could be the reason for that?
Answer:
It is due to the magnetic field produced by electric charges in motion.

Question 13.
Why does the picture get distorted?
Answer:
Due to motion of electrons that form the picture is affected by the magnetic field of bar magnet.

Question 14.
Is the motion of electrons reaching the screen affected by the magnetic field of the bar magnet?
Answer:
Yes. The motion of electrons reaching the screen is affected by the magnetic field of the bar magnet.

Question 15.
Can we calculate the force experienced by a charge moving in a magnetic field?
Answer:
Yes, If the force is F, it is given by the expression F = qvB.

Question 16.
Can we generalize the equation for magnetic force on charge when there is an angle ‘0’ between the directions of field “B” and velocity “v”?
Answer:
No, Then force F is given by the formula F = qvB sin θ.

Question 17.
What is the magnetic force on the charge moving parallel to a magnetic field?
Answer:
When the charge moves parallel to the magnetic field the value of “θ” becomes zero. In the equation F = qvB sin θ, since θ = θ, the value of force F also becomes zero.

Question 18.
What is the direction of magnetic force acting on a moving charge?
Answer:
By applying right hand rule we can guess the direction of magnetic force acting on a moving charge is the “thumb” direction.

10th Class Physics Textbook Page No. 221

Question 19.
Can you determine the magnetic force on a current carrying wire which is placed along a magnetic field?
Answer:
F = BIl sin θ. If the current carrying wire is placed along direction field θ = 0.
∴ F = 0

Question 20.
What is the force on the wire if its length makes an angle ‘θ’ with the magnetic field?
Answer:
F = Bqv sin θ or F = Bil sin θ, where ‘i’ is current. WorhA
Here B = magnetic induction, q = charge, v = velocity of the charge and ‘θ’ is the angle between direction of field and velocity.

10th Class Physics Textbook Page No. 222

Question 21.
How could you find its (current carrying wire) direction?
Answer:
We can find by using right hand rule.

Question 22.
Is the direction of deflection observed experimentally same as that of the theoretically expected one?
Answer:
Yes. But it depends on polarities of the horse shoe magnet.

Question 23.
Does the right hand rule give the explanation for the direction of magnetic force exerted by magnetic field on the wire?
Answer:
The right hand rule does not help us to explain the reason for deflection of wire.

Question 24.
Can you give a reason for it (deflection of wire)?
Answer:
There exists only magnetic field due to external source. When there is a current in the wire, it also produces a magnetic field. These fields overlap and give non-uniform field. This is the reason for it.

10th Class Physics Textbook Page No. 223

Question 25.
Does this deflection fit with the direction of magnetic force found by right hand rule?
Answer:
Yes. This deflection fits with the direction of magnetic force found by right hand rule.

Question 26.
What happens when a current carrying coil is placed in a uniform magnetic field?
Answer:
It gets deflected since magnetic lines of force are perpendicular to the length of the coil.

Question 27.
Can we use this knowledge to construct an electric motor?
Answer:
Yes. This is the principle of electric motor.

Question 28.
What is the angle made by AB and CD with magnetic field?
Answer:

AB and CD are at right angles to the magnetic field.

10th Class Physics Textbook Page No. 224

Question 29.
Can you draw the direction of magnetic force on sides AB and CD?
Answer:
Yes. The direction of magnetic force on sides AB and CD can be determined by applying right hand rule.

Question 30.
What are the directions of forces on BC and DA?
Answer:

ADBC, magnetic force pulls the coil up and at DA magnetic force pulls it down.

Question 31.
What is the net force on the rectangular coil?
Answer:
Net force on the rectangular coil is zero.

Question 32.
Why does the coil rotate?
Answer:

The rectangular coil rotates in clockwise direction because of equal and opposite pan’ of forces acting on the two sides of the coil.

Question 33.
What happens to the rotation of the coil if the direction of current in the coil remains unchanged?
Answer:
The coil comes to halt and rotates in anti-clockwise direction.

Question 34.
How could you make the coil rotate continuously?
Answer:
If the direction of current in coil, after the first half rotation, is reversed, the coil will continue to rotate in the same direction.

10th Class Physics Textbook Page No. 225

Question 35.
How can we achieve this (convertion of electrical energy to mechanical energy)?
Answer:
Brushes B₁ and B₂ are used to achieve this.

Question 36.
What happens when a coil without current is made to rotate in magnetic field?
Answer:
When the coil rotated due to the change in magnetic flux electricity is generated.

Question 37.
How is current produced?
Answer:
The current is produced from the battery to the coil.

Question 38.
Why is there a difference in behaviour in these two cases?
Answer:
The A.C. supply changes its direction a number of times in a second. But D.C. is unidirectional current. So there is a difference in the behaviour of the metal ring in these two cases.

Question 39.
What force supports the ring against gravity when it is being levitated?
Answer:
The magnetic force developed in the coil of copper wire supports the ring against gravity when it is being levitated.

10th Class Physics Textbook Page No. 226

Question 40.
Could the ring be levitated if DC is used?
Answer:
The metal ring is levitated because the net force on it should be zero according to Newton’s second law.

Question 41.
What is this unknown force acting on the metal ring?
Answer:
The change in polarities at certain intervals at the ends of the solenoid causes the unknown force acting on the metal ring.

Question 42.
What is responsible for the current in the metal ring?
Answer:
The field through the metal ring changes so that flux linked with the metal ring changes and this is responsible for the current in metal ring.

Question 43.
If DC is used, the metal ring lifts up and falls down immediately. Why?
Answer:
The flux linked with metal ring is zero. When the switch is on, at that instant there should be a change in the flux linked with ring. So the ring rises up and falls down. If the switch is off, the metal ring again raises up and falls down. There is no change in flux linked with ring when the switch is off.

10th Class Physics Textbook Page No. 227

Question 44.
What could you conclude from the above analysis (metal ring lifts up and falls down)?
Answer:
The relative motion of the magnet and coil sets up a current in the coil.

10th Class Physics Textbook Page No. 228

Question 45.
What is the direction of induced current?
Answer:
The direction of the induced current is such that it opposes the charge that produced it.

Question 46.
Can you apply conservation of energy for electromagnetic induction?
Answer:
Yes, we can apply. The mechanical energy is converted into electrical energy.

10th Class Physics Textbook Page No. 229

Question 47.
Can you guess what could be the direction of induced current in the coil in such case?
Answer:
The direction of the induced current in the coil must be in anti-clockwise direction.

Question 48.
Could we get Faraday’s law of induction from conservation of energy?
Answer:
Yes, we can get. Here we have to ignore the friction everywhere.

10th Class Physics Textbook Page No. 230

Question 49.
Can you derive an expression for the force applied on crosswire by the field “B”?
Answer:
Yes. The force applied F = BIl.

10th Class Physics Textbook Page No. 232

Question 50.
How could we use the principle of electromagnetic induction in the case of using ATM card when its magnetic strip is swiped through a scanner? Discuss with your friend or teacher.
Answer:
If the card is moved through a card reader, then a change in magnetic flux is produced in one direction, which induced potential or EMF. The current received by the pickup coil goes through signal amplification and translated into binary code, so that it can be read by computer.

Question 51.
What happens when a coil is continuously rotated in a uniform magnetic field?
Answer:
An induced current is generated in the coil.

Question 52.
Does it (continuous rotation of coil) help us to generate electric current?
Answer:
Yes. Continuous rotation of coil helps us to generate electric current.

10th Class Physics Textbook Page No. 233

Question 53.
Is the direction of current induced in the coil constant? Does it change?
Answer:
Yes, it changes. When the coil is at rest in vertical position, with side (A) of coil at top position side (B) at bottom position, no current will be induced in it.

Question 54.
Can you guess the reason for variation of current from zero to maximum and vice-versa during the rotation of coil?
Answer:
The reason for variation of current from zero to maximum and vice-versa during the rotation of coil current generated follows the same pattern so that in first half except that the direction of current is reversed.

Question 55.
Can we make use of this current? If so, how?
Answer:
Two carbon brushes are arranged in such a way that they press the slip rings to obtain current from the coil. When these brushes are connected to external devices like TV, Radio we can make them work with current supplied from ends of carbon brushes.

10th Class Physics Textbook Page No. 234

Question 56.
How can we get DC current using a generator?
Answer:
By connecting two half-slip rings instead of a slip ring commutator on either side to the ends of the coil we can get D.C. current.

Question 57.
What changes do we need to make in an AC generator to be converted into a DC generator?
Answer:
Instead of two slip rings, we have to use a slip ring commutator to change A.C. generator into a D.C. generator.

10th Class Physics 12th Lesson Electromagnetism Activities

Activity – 2

Question 1.
Show that the magnetic field around a bar magnet is three dimensional and its strength and direction varies from place to place.
Answer:

• Take a sheet of white paper and place it on the horizontal table.
• Place a bar magnet in the middle of the sheet.
• Place a magnetic compass near the magnet it settles to a certain direction.
• Use a pencil and put dots on the sheet on either side of the needle. Remove the compass. Draw a small line segment connecting the two dots. Draw an arrow on it from south pole of the needle to north pole of the needle.
• Repeat the same by placing the compass needle at various positions on the paper. The compass needle settles in different directions at different positions.
• This shows that the direction of magnetic field due to a bar magnet varies from place to place.
• Now take the compass needle to places far away from magnet, on the sheet and observe the orientation of the compass needle in each case.
• The compass needle shows almost the same direction along north and soiath at places far from the magnet.
• This shows that the strength of the field varies with distance from the bar magnet.
• Now hold the compass a little above the table and at the top of the bar magnet.
• We observe the deflection in compass needle. Hence we can say that the mag¬netic field is three dimensional i.e., magnetic field surrounds its source.
• From the above activities we can generalize that a magnetic field exists in the region surrounding a bar magnet and is characterized by strength and direction.

Activity – 3

Question 2.
Explain how you draw magnetic lines of force in the magnetic field.
(OR)
What is the name given to the imaginary lines joining from north pole to south pole of a bar magnet called? Explain how you can draw those lines around a bar magnet.
Answer;
These lines are called magnetic lines of forces.

Procedure:

1. Take a white drawing sheet.
2. Place a marine compass at the centre of the sheet.
3. Draw a line which shows north and south of the earth on the drawing sheet.
4. Now remove the compass needle and place a bar magnet at the centre of the sheet showing north of the bar magnet pointing north of the earth.
5. Place the magnetic compass near the bar magnet without contact. The needle comes to rest after oscillations.
6. Locate the end of the pointer with pencil. Now place the compass needle at this point and once again notice the end of the pointer.
7. We can repeat the same around the magnet, and draw all the points with the help of the pencil.
8. We can draw the lines taking the needle too far to the magnet and we can observe the orientation of needle of compass.
9. So we can conclude that the strength of field varies with distance from the bar magnet.
10. These lines of force are from north of the bar magnet to south of the bar magnet.

Activity – 4

Question 3.
Explain the direction of magnetic field around the straight conductor carrying current.
(OR)
What field would be formed around straight conductor carrying current? How do you find the direction of that field experimentally?
Answer:
Magnetic field would be formed around current carrying conductor.

Procedure:

1. Take a wooden plank and make a hole and place il on the table.
2. Place a stand on the plants, and suspend a c opper wire from the stand and see that it passes through the hole made to the plank.
3. Connect a battery and switch to this wire in series. Place some magnetic needle at the hole.
4. If the current is passed through the wire, the magnetic needle deflects and it is directed as the tangent to the circle
5. If the current flows in downward direction, the field lines are in anti-clockwise direction and if the current flows in upward direction, the field lines are in clockwise direction.
6. The direction ol the current and magnetic fines of force can be easily explained with the help of right hand thu mb rule. If you hold the current carrying conductor with your right hand grip stretching the thumb, the direction of the I humb shows the direction of the current, the direction of the other four fingers shows direction of magnetic lines of force.

Activity 5

Question 4.
Explain the direction of magnetic field due to circular coil.
Answer:

Procedure :

1. Take a thin wooden plank and cover it with whitepaper.
2. Make two holes to the plank and pass insulated copper wire through the holes and wind the wire 4 to 5 times through the holes such that it looks like a coil.
3. The ends of the wire are connected to the battery terminals.
4. Now place a compass needle at the centre of the coil.
5. Put dots on either side of the compass. Repeat this by keeping at the dots. We can observe that field lines are circular.
6. Here the direction of the field is perpendicular to the plane of the coil.
7. The direction of the magnetic field due to coil points towards you when the current in the coil is in anti-clockwise direction.
8. When you curl your right hand fingers in the direction of current, thumb gives the direction of magnetic field.

Activity – 6

Question 5.
Explain the magnetic field due to solenoid.
(OR)
What is the name given to the device which is a long wire wound in a close pack helix? Find the direction of magnetic field around that device.
Answer:
It is called solenoid.

Procedure :

1. Take a wooden plank covered with white paper.
2. Make holes on its surface.
3. Pass copper wire through the holes.
4. Join the ends of the coil to a battery through a switch.
5. Current passes through the coil, when we switch on the circuit.
6. Now sprinkle iron filings on the surface of the plank, around the coil. Then orderly pattern of iron filings is seen on the paper.
7. The iron filings arrange themselves in orderly way and look like lines of force.
8. The long coil is known as solenoid. The direction of the field due to solenoid is determined by using right hand rule.
9. One end of the solenoid behaves like a north pole and the other behaves like south pole.
10. Outside the solenoid the direction of the field lines of force is from north to south while inside the direction is from south to north. Thus the magnetic field lines are closed loops.
11. Hence electric charges in motion produce magnetic field.

Activity – 8

Question 6.
Explain the field lines due to horse-shoe magnet between its poles.
(OR)
Which field is set up between poles of a horse-shoe magnet? Explain the field lines due to horse magnet between its poles.
Answer:
Non-uniform magnet is set up between poles of a horse shoe magnet.

Procedure :

1. The field in between north and south pole of horse-shoe magnet are straight and parallel.
2. If the wire is passing perpendicular to the paper, the magnetic lines of force are concentric circles, when the current is passed.
3. The direction of field lines due to the wire in upper part coincides with the direction of field lines of horse-shoe magnet.
4. The direction of field lines by the wire in lower part is opposite to the direction of field lines of horse-shoe magnet.
5. Hence the net field in upper part is strong and in the lower part is weak.
6. Hence a non-uniform field is created around the wire.

Activity – 9

Question 7.
Explain electromagnetic induction.
(OR)
Which current will levitate the ring in the following figure? Explain the experimental activity.
Answer:
AC will levitate the ring.

Procedure :

1. Fix a soft iron cylinder on the wooden base vertically.
2. Wind copper wme around the soft iron.
3. Take a metal ring which is slightly greater in radius than the radius of soft iron cylinder and insert it through the soft iron cylinder.
4. Connect the ends of the coil to an AC source and switch on the current.
5. Here metal ring levitates on the coil (appears to rise and floats in the air).
6. In this experiment we can conclude that if AC current is used, the magnetic induction changes in both magnitude and direction in the solenoid and in the ring. The field through the metal ring changes, so that flux linked with the metal ring changes.
7. If DC current is used, the metal ring lifts up and falls down immediately.

AP State Board Syllabus AP SSC 10th Class Biology Important Questions Chapter 10 Natural Resources.

AP State Syllabus SSC 10th Class Biology Important Questions 10th Lesson Our Environment

10th Class Biology 10th Lesson Natural Resources 1 Mark Important Questions and Answers

Question 1.
Recently a new programme was launched in our state known as “Vanam – Manain”. Prepare any two slogans to promote the programme.
Answer:
a) Save forest, forest will save you.
b) Grow the plants and get the fresh air.

Question 2.
Suggest any two practices suitable to farmers with less water resources.
Answer:

1. Construction of percolation tanks (or) Soak pits
2. Irrigation techniques like drip irrigation and usage of sprinklers.

Question 3.
Why should we conserve forests? Give two reasons.
Answer:
a) Forests serve as lungs for the world. They purify the air and protect the earth from greenhouse effect and global warming,
b) Forests are rich habitats for plants

Question 4.
Ravi observed symbol on the plastic water bottle purchased by him. What does this symbol indicate? and animals.
Answer:
The symbol on the plastic bottle indicates that the bottle is made from recycled plastic and after its use it can be recycled.

Question 5.
Write any two suggestions for the conservation of biodiversity at your village.
Answer:

1. Protecting and preserving the natural habitats of birds and animals.
2. Replace the wood products with alternative sources.
3. Using Recycled products and following the 4’R Principle in day to day life.

Question 6.
Suggest any two activities to check soil erosion in your school.
Answer:

1. Observe the school ground after the rain.
2. Conduct a field project on soil erosion.

Question 7.
To create awareness on “Water conservation” in your locality, what slogan you will suggest?
Prepare two slogans on ‘Save Water’ propaganda.
Answer:
“Don’t Waste Water”.
“Save every drop”.
“Water is life”.

Question 8.
The symbol is there on the item you bought. What it instructs? (OR)
What does the given logo indicate? What does it mean?

Answer:
It is the Recycle logo. It indicates that the item we bought is prepared from recycled materials or the item can be recycled after use.

Question 9.
What happens if the forest area decreases rapidly?
Answer:
If the forest area decreases

1. It destroys wildlife habitat.
2. It increases soil erosion.
3. It releases green house gases into the atmosphere contributing to global warming.
4. It also harms people who relay on forest for their survival, hunting and gathering, harvesting forest products or using timber and firewood.

Question 10.
Write two activities which you are performing to save electricity.
(OR)
Write any two measures vou take in your home to reduce the consumption of electricity.
Answer:

1. We can reduce the consumption of electricity by putting off the fans and lights when there is no need.
2. We can use LED (Lighting Emitting Device) bulbs to save electricity.
3. To shut down laptops and computers when they are not in use.

Question 11.
Prepare two slogans on protecting non-renewable resources.
Answer:

1. Use Biofuel – Reduce Fossil Fuel.
2. Use alternative resources – Save the environment.

Question 12.
Write two examples for non-renewable resources.
Answer:
Examples for non-renewable resources are coal, petroleum and natural gas.

Question 13.
What is sustainable development? Is it needful for us?
Answer:
When we use the environment In ways that ensure we have resources for the future, It Is called sustainable development. It Is needed because development and conservation can coexist In harmony.

Question 14.
What are examples for natural resources?
Answer:
Examples for natural resources are water, soil, forests, flora, fauna, etc.

Question 15.
What are percolation tanks?
Answer:
Percolation tanks are normally earthen dams with masonry structures where water may overflow.

Question 16.
What are Kharif crops?
Answer:
Crops grown In the rainy season are termed as Kharif crops, e.g: Paddy, maize, millet and cotton crops.

Question 17.
What are Rabi crops?
Answer:
The crops that are grown only in winter season are generally called Rabi crops, e.g.: Wheat, Gram and Mustard.

Question 18.
What is the average fall of ground water level in Andhra Pradesh state during the period of 1998 – 2002?
Answer:
The average fall of ground water level In Andhra Pradesh state during the period of 1998 – 2002 Is 3 meters.

Question 19.
Which agency in villages of Warangal district helped in recharging wells that were being dried up?
Answer:
Centre for water solidarity (Secundrabad, T.S.) helped In recharging wells that were drying up In the villages.

Question 20.
Give examples for micro irrigation techniques.
Answer:
Drip irrigation, sprinklers are the examples for micro irrigation techniques.

Question 21.
Mow did the boundaries between the villages were fixed in ancient times?
Answer:
In ancient times village boundaries were decided upon a water shed (Land between water sources usually of two rivers or streams) basis fixed at the common point of the drainage system In between two villages by the expert farmers In the village.

Question 22.
Expand ICRISAT.
Answer:
International Crop Research Institute for Semi-Arid Tropics.

Question 23.
What is the other name for Sri Rama Sagar Project?
Answer:
Sri Rama Sagar Project also known as the Pochampadu project on the Godavari river,

Question 24.
What is the use qf planting Gliricidia on field bunds?
Answer:
Planting Gliricidia on field bunds help In strengthen them and make the soli nitrogen-rich.

Question 25.
What is the micro irrigation system that can reduce water consumption by 70%?
Answer:
Drip irrigation can reduce water consumption by 70%.

Question 26.
Who predicted that by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity ?
Answer:
The Food and Agriculture Organisation (FAO) of the united nations has predicted that by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity.

Question 27.
What happens if we use resources wisely?
Answer:
If resources are used wisely and efficiently they will last much longer. Through conservation people can reduce waste and manage natural resources wisely.

Question 28.
Give an example of country where restrictions on water usage were imposed.
Answer:
In Australia restrictions were imposed on activities like, watering lawns by using sprinkler systems, washing vehicles, using house pipes to clean paved areas, and refilling swimming pools.

Question 29.
Why are the natural resources used up quickly?
Answer:
The population of human beings has grown enormously in the past two centuries. Billions of people use up resources quickly as they eat food, build houses, produce goods and burn fuel for transportation and electricity.

Question 30.
What happens if we damage a forest resource?
Answer:
Harm to animals that may be forced to find new habitats. If we damage a forest resource indiscriminately the depletion of resources occur and we may have to face problem for water and timber in future.

Question 31.
What are the results of deforestation?
Answer:
Deforestation destroys wild life habitats and increases soil erosion and also releases green house gases into atmosphere, contributing to global warming.

Question 32.
How the people in China and Mexico recycle paper? (OR)
Give an example of recycling paper by the people. What is the use of recycling paper?
Answer:
People in China and Mexico reuse much of their waste paper, including writing paper, wrapping paper and card board.

Question 33.
How the soil is important for us ? How the soil is importane for us?
Answer:
Soil is vital to food production and also important to plants that grow in the wild.

Question 34.
What are the reasons for depletion of nutrients in soil?
Answer:
Poor farming methods, such as repeatedly planting the same type of crop in the same place cause depletion of nutrients in the soil.

Question 35.
What is biodiversity?
Answer:
Biodiversity is the variety of living things that populate the Earth.

Question 36.
How are people speeding up the loss of biodiversity?
Answer:
Through hunting, pollution, habitat destruction, people are speeding up the loss of biodiversity.

Question 37.
How many plant species are being used by us for medicines world wide?
Answer:
We use between 50,000 to 70,000 plant species for medicines world wide.

Question 38.
What is selective harvesting?
Answer:
The practice or removing individual plants or small groups of plants leaving other plants standing to anchor the soil is called selective harvesting.

Question 39.
How are fossil fuels produced?
Answer:
The fuels that are produced from the remains of ancient plants and animals are called fossil fuels. They include coal, petroleum and natural gas.

Question 40.
What are the alternate sources of energy?
Answer:
The alternate sources of energy are sun, wind and water.

Question 41.
What are the other products made from petroleum?
Answer:
Plastic, synthetic, rubber, fabrics like nylon, medicines, cosmetics, waxes, cleaning products, medical devices, etc., are the other products made from petroleum.

Question 42.
Which plant’s seeds are used for the production of bio-fuel?
Answer:
Seeds from the Jatropa Curcas plant are used for the production of bio-fuel.

Question 43.
How does the mining method, Mountain Top Removal mining (MTR) devastate the environment?
Answer:
The mining method Mountain Top Removal mining devastate the environment. They destroy soil, plants and animal habitats.

Question 44.
In which country car manufacturers recycle many raw materials used in making automobiles?
Answer:
In Japan car manufacturers recycle many raw materials used in making automobiles.

Question 45.
In which country nearly one third of the iron produced comes from recycled automobiles?
A. In the United States, nearly one-third of the iron produced comes from recycled automobiles.

Question 46.
What does the Indian tradition teach us?
Answer:
The Indian tradition teaches us that all forms of life – human, animal and plant are so closely inter linked that disturbance of one gives rise to imbalance in the other.

Question 47.
Expand IUCN.
Answer:
IUCN stands for International Union for the Conservation of Nature.

Question 48.
How is IUCN planning to protect wild life and habitats?
Answer:
IUCN monitors the status of endangered wild life, threatened national parks and preserves.

Question 49.
What are the four R’s to save the environment?
Answer:
Reduce, Reuse, Recycle, Recover are the four R’s to save the environment.

Question 50.
How did Amritha Devi and her daughters protest against the king’s order?
Answer:

1. Amritha Devi and her daughters, followed by villagers, who clung to trees in the forest surrounding their village and laid down their lives to save them.
2. They protested against the king’s order to collect wood for the construction of his palace.

Question 51.
Write a method of soil conservation.
Answer:
One soil conservating method is called contour strip cropping. Several crops such as corn, wheat and clover are planted to alternating strips across a slope or across the path of the prevailing wind.

Question 52.
What is the rate of extinction by the estimation of the scientists?
Answer:

1. Scientists estimate that the current rate of extinction is 1,000 times the natural rate through hunting, pollution, habitat destruction.
2. Based on various estimates of the number of species on Earth, we could be losing anywhere from 200 to 1,00,000 species each year.

Question 53.
What is the need to protect biodiversity?
Answer:
We need to protect biodiversity to ensure plentiful and varied food sources. Biodiversity is important for more than just food because many plant species are being used for medicines.

Question 54.
Mention two ways in which water harvesting can be undertaken?
Answer:
The two ways by which water harvesting can be undertaken are

1. Capturing run off water from, rooftops.
2. Capturing run off water from local catchments.

Question 55.
On the basis of the issues raised in the chapter management of natural resources, what changes you in corporate in your lifestyle in a move towards a sustainable use of our resources?
Answer:
I would incorporate the maximum of four R’s i.e., reduce, recycle, reuse and recover in my lifestyle in a move towards a sustainable use of our resources.

10th Class Biology 10th Lesson Natural Resources 2 Marks Important Questions and Answers

Question 1.
Rahul remarked that different human activities are responsible for global warming.
What might be the reasons for his statement?
Answer:

1. Deforestation.
2. Industrialisation and urbanization.
3. Conversion of agriculture lands into residential areas.
4. Home appliances like A/C, refrigerators, vehicle pollution.
5. Population explosion.

Question 2.
What steps do you take to improve natural resources?
Answer:

1. Motivate the people to conserve water.
2. Try to avoid wastage of water whenever possible.
3. Plantation in the vacant lands.
4. Educating the farmer regarding proper utilization of water for irrigation.
5. Encourage the people to recycle the water wherever possible.

Question 3.
Proper utilisation of natural resources is the way to show gratitude to our nation.
Can you support this statement? Give your argument.
Answer:

1. Natural resources of a nation influence its economical and social development.
2. Natural resources are freely available in nature and help in many activities and development of people.
3. The generation of natural resources take a lot of time.
4. They disappear by indiscriminate usage.
5. So proper utilization of natural resources is the way to show gratitude to our nation.

Question 4.
The humans are utilising natural resources indiscriminately. These resources are decreasing more rapidly. Guess what will be the consequences in future?
Answer:
Indiscriminate usage of natural resources causes the following consequences.

1. Reduction in rainfall
2. Drought will occur.
3. Atmospheric temperature becomes increase.
4. The rare species become extinct.

Question 5.
Write any four slogans on the conservation of natural resources.
Answer:
Slogans:

1. Waste water today – live in desert tomorrow
2. Practice eco-friendly methods.
3. Use natural resources judiciously.
4. Save nature – Save future.

Question 6.
There is an increase in the atmospheric temperature year by year. If it continues, guess and write what would be the consequences?
Answer:
If the temperature on earth increases, the consequences would be as follows.
a) All the glaciers and the frozen ice in the polar region start melting leading to rise in the sea water levels.
b) It results in the submergence of low lying coastal areas throughout the world. Millions of people of those areas would lost their homes.
c) Changes in rainfall patterns take place and it result in the occurance of droughts and decrease in crop production.
d) Global warming results in climate change which cause the breakout of climatic sensitive diseases like Malaria, Dengue, Diarrhoea, etc.

Question 7.
There is water scarcity in Ravi’s village during summer. He wants to conduct a rally to create awareness regarding conservation of water. Write any four slogans required to conduct this rally.
Answer:

1. Water is life.
2. Save water – Save a life.
3. Today’s rain water is tomorrow’s life saver.
4. No matter your occupation, water conservation is your obligation.

Question 8.
What steps you take to conserve the biofuels in your daily life?
Answer:

1. Development and usage of alternative energy resources in place of bio-fuels.
2. Minimise the usage of bio-fuels whenever possible.
3. Use public transport, ride by bicycle and walking regularly.
4. Use and purchase energy efficient appliances to save bio-fuels.

Question 9.
Why do we use fossil fuels judiciously?
Answer:

1. Fossil fuels were produced from the remains of ancient plants and animals.
2. They include coal, petroleum (oil) and natural gas.
3. We need to use fossil fuels judiciously because they are non – renewable resources.
4. We need to conserve fossil fuels so we don’t run out of them.
5. The pollution caused by them when burnt, to limit our fossil fuel use.
6. Future generations may not get these resources.
7. Balance in the nature will be disturbed.
8. Electricity production will be stopped.
9. Vehicles running with fossil fuels become useless.

Question 10.
Write two suggestions to create awareness on groundwater conservation.
Answer:

1. We need to adapt different methods to Improve the quality and increase the quantity of groundwater.
2. We should dig water harvesting pits for every house.
3. We should clean the silt, mud fill in tanks and ponds.
4. We should prohibit the establishment of borewells for extraction of groundwater for agricultural and Industrial use.
5. These measures will improve quality and quantity of groundwater.

Question 11.
What is the importance of 4R’s in achieving the goal of “Swachh Bharat”?
Answer:

1. Reduce the production of garbage.
2. Reuse the garbage for the production of manure and electricity.
3. Recycle the garbage by separating It as dry and wet garbage.
4. Recover the plants.

Question 12.
Suggest four measures to conserve fossil fuels.
Answer:
Measures to conserve fossil fuels:

1. Usage of alternatives to fossil fuel.
2. Minimise the usage of fossil fuel.
3. Walk, ride by bicycle and use public transportation whenever possible.
4. Purchase energy efficient appliances.
5. Turn off light and other electronics when you are not using them.

Question 13.
The indiscriminate digging of Borewells may result in what type of consequences in future?
Answer:

1. Due to over drilling of borewells and pulling out water by electric motors, the ground water level Is decreasing day by day.
2. It Is goes on without recharging, ground water becomes scarce.
3. It shows impact on agriculture and the productivity will decrease.
4. Fluorine levels In ground water will increase.
5. Sometimes, saline water may intrude Into the interior places of land and water becomes unfit for consumption.
6. Farmers have to drill the bore wells to more depths which Increase the losses for them.

Question 14.
Ramaiah made broad bed furrow around his field under employment guarantee scheme. Guess the reasons for if. If all the farmers of your village work together, will their water scarcity meet?
Answer:
The reason for Ramaiah making broad bed furrow around his field was, it is useful to conserve soil and water, fertilizer application weeding operations. It also conserves rain water.

The farmers are over coming the water scarcity by sharing water available in the village. They formed groups of farmer including large and small ones who would use the same water resource. Farmers were also motivated to use irrigation techniques like drip irrigation.

Question 15.
What are renewable sources and non-renewable resources?
Answer:
Renewable resources: Resources that can be replaced after they are used are called renewable resources.
Ex: Air, water and soil.
Non-renewable resources: Some other resources, cannot be replaced at all: Once they are used up they are gone forever and are called non renewable resources.
Ex: Coal, Petroleum, Natural gas (fossil fuels).

Question 16.
How do people waste natural resources?
Answer:

1. People often waste natural resources.
2. Animals are over hunted, forests are cleared, exposing land to wind and water damage.
3. Fertile soil is exhausted and lost to erosion because of poor farming practices.
4. Fuel supplies are depleted.
5. Water and air are polluted.
6. Water resources is indiscriminately used for crop growth.

Question 17.
How do people use the forest resources differently?
Answer:

1. The need to conserve resources often conflicts with other needs.
2. For some people, a forest area may be a good place to put a farm.
3. A timber company may want to harvest the area’s trees for construction materials.
4. A business company may want to build a factory or a shopping mall on the land.

Question 18.
What are die effects of deforestation?
Answer:

1. Deforestation destroys wild life habitats and increases soil erosion.
2. It also releases green house gases into the atmosphere, contributing to global warming,
3. Deforestation accounts for 15 per cent of the world’s green house gas emissions.
4. Deforestation also harms the people who rely on forests for their survival, hunting and gathering, harvesting forest products, or using the timber for firewood.

Question 19.
In your opinion What are the causes for soil erosion?
Answer:

1. Soil erosion is caused by poor farming methods such as repeatedly planting the same type of crop in the same place.
2. These methods deplete nutrients in the soil.
3. Soil erosion Is also caused by water and wind currents.
4. When farmers plough up and down hills, soil erosion occurs.
5. Overgrazing by cattle also causes soil erosion.
6. Natural floods causes the extensive damage to the top layer of the soil.

Question 20.
What is Biodiversity? Explain.
(OR)
What is the importance of biodiversity?
Answer:

1. Biodiversity is the variety of living things that populate the earth.
2. The products and benefits we get from nature rely on biodiversity.
3. We need to protect biodiversity to ensure plentiful and varied food sources.
4. Biodiversity is important for more than just food. For instance we use between 50,000 to 70,000 plant species for medicines world wide.

Question 21.
How can we use the fossil fuels carefully?
Answer:
We can use the fossil fuels carefully by taking the following measures.

1. Turn off lights and other electronics when we are not using them.
2. Purchase energy-efficient appliances.
3. Walk, ride a bicycle, if the distance is less.
4. Use public transportation whenever possible.
5. It is better to prefer public transport system like bus or train, instead of travel in personal vehicles.

Question 22.
Why the prices of aluminium and iron are expensive?
Answer:
Earth’s supply of raw material resources is in danger. Many mineral deposits that have been located and mapped have been depleted. As the ores for minerals like aluminium and iron become harder to find and extract, their prices go up.
This makes tools and machinery more expensive to purchase and operate.

Question 23.
What are the effects of mining?
Answer:

1. Many mining methods such as Mountain Top Removal mining (MTR) devastate the environment.
2. They destroy soil, plants and animal habitats.
3. Many mining methods also pollute water and air, as toxic chemicals leak into the surrounding ecosystem.

Question 24.
What did Smt. Indira Gandhi said, while launching the world conservation strategy in India on 6th March 1980?
Answer:
“The interest in conservation is not a sentimental one but the discovery of a truth well known to our ancient stages. The Indian tradition teaches us that all forms of life- human, animal and plant – are so closely inter-linked that disturbance in one gives rise to imbalance in the other” said by Smt. Indira Gandhi.

Question 25.
What are the steps taken by the government to conserve resources?
Answer:

1. Government enacts laws defining how land should be used and which areas should be set aside as parks and wild life preserves.
2. The government enforces laws designed to protect the environment from pollution, such as requiring factories to install pollution control devices and also provide incentives for conserving resources.

Question 26.
What is the necessity of sustainable management of natural resources? Out of the two methods reuse and recycle which one would you suggest to practice and why?
Answer:

1. Sustainable management of natural resources is necessary to Increase the over all life of natural resources specially non renewable resources and also to control the environmental pollution.
2. Both reuse and recycle are the good choice.
3. Reuse: If we reuse something then the cost of recycle will be saved.
4. Recycle: It is not necessary that each and everything can be reused, so after getting recycled the life of the resource will be enhanced.

Question 27.
“Burning fossil fuels is a cause of global warming”. Justify this statement?
Answer:

1. Fossil fuels are composed of carbon, hydrogen, nitrogen and sulphur.
2. When these are burnt they produce CO₂, H₂O, Oxides of Nitrogen and Sulphur.
3. Incomplete combustion of fossil fuels produces green house gases such as CO₂,
4. If huge amount of fossil fuels are burnt, It would produce high amount of CO₂ resulting intense global warming.

Question 28.
Can you suggest some changes in your school which would make it environment friendly?
Answer:
The changes that would make my school environment friendly are

1. Save energy by turning off lights that we are not using.
2. I will suggest to buy recycled paper for decoration and other purposes.
3. Use writing paper on both the sides.
4. Growing trees and plants all around the play ground.

Question 29.
What is the necessity of replenishment of forest? State four reasons.
Answer:
The replenishment of forest is necessary because of the following reasons.

1. It is used to conserve soil.
2. It provides shelter to wild animals.
3. It reduces atmospheric pollution.
4. It controls flood and increases frequency of rainfall.

10th Class Biology 10th Lesson Natural Resources 4 Marks Important Questions and Answers

Question 1.
Forest is renewable resource. But, each year, the Earth loses about 36 million acres of forest. In this type of situation, what suggestions do you give to save forests from turning into non-renewable resources ?
Answer:

1. Forests are the lungs of the world. So I will suggest the following measures to save forests from turning into non-renewable resources.
2. Sustainable forestry practices for ensuing resources into the future.
3. Low impact logging practices, harvesting with natural regeneration in mind. Prevention of removing all the high value trees or all the largest trees from the forests. Recycling methods should be adopted.
4. Replace wood products with alternative sources.
5. Preventing forest fires.
6. Implementing methods like agro forestry, social forestry crop rotation, green plantation, etc. are essential.

Question 2.
What are four R’s? Explain how they help to conserve the environment?
(OR)
Write about the 4 ‘R’s needed for the protection and conservation of environment.
Answer:
By pursuing the maximum of four R’s i.e., Reduce, Reuse, Recycle and Recover, we can save the environment in an effective way.

1. Reduce : It means to use less, I would save electricity by switching off unnecessary lights and fans, prefer walking or cycling than using a vechicle, turn off the engine of car at red light, repair leaky taps and would not waste food.
2. Recycle: It means to collect used things like plastic, paper, galss and metal items and recycle these materials to make required things instead of synthesising or extracting fresh plastic, paper, glass or metal.
3. Reuse: It refers to use things again and again. For example instead of throwing away used envelops, they can be used by pasting new labels.
4. Recover: We should implement ‘recover’ to prevent environmental threat. For example when we cut trees to construct industries or roads for transportation, it is important to grow trees in another areas.

Question 3.
What steps you would like to follow on your part to conserve bio-diversity?
Answer:

1. Biodiversity is the variety of living things that populate the earth.
2. To conserve biodiversity we should avoid hunting.
3. Sustainable forest conservation methods should be followed.
4. I will actively participate Vana Mahosthavam programmes.
5. I will educate and encourage people and make them participate in conservation programmes.
6. Create awareness programmes in and around school.
7. Writing slogans and also make some posters about conservation of biodiversity
8. Judicious use of electricity wherever possible.
9. Finding out of various alternative sources of energy.
10. Plant the saplings in the habitat.
11. Encouraging of social forestry.

Question 4.
Observe the pie diagram showing water resources available in our state for agriculture and answer the given questions.
A) Which water resource is using more for agriculture?
B) What are the consequences of excess utilization of underground water?
C) Which water resource should be utilized for agriculture?
D) What are the alternative ways to increase the underground water resources?

Answer:
A) Ground water.
B) Underground water table will be depleted and scarcity of drinking water will arise.
C)

1. Tanks should be constructed to harvest with rain water.
2. Projects should be constructed across the rivers to store water that can be utilized for agriculture.

D)

1. Construction of rain water storage structures on large scale.
2. Constructing soaking or percolation pits.
3. Contour field bunding.
4. Recharge of wells by building dykes or barriers in the nalla.
5. Plantation in waste lands.
6. Adapting micro irrigation techniques.
   (Any two points you can write)

Question 5.
Forests are renewable resource. Write four sentences supporting this.
(OR)
“Forest is a renewable resource”. Do you agree? Justify.
Answer:

1. Forests are rich habitat for plants and animals. Forests serve as lungs for the world and a bed of nutrients for new fife to prosper.
2. Forest’s pure air protects the earth from green house effect by removing carbon dioxide from the atmosphere and converts it into oxygen.
3. Many fruits, medicines, dyes, sandle wood and bamboo is obtained from forest by local people.
4. Forest provide employment to large number of people and also help in generating revenue.

Question 6.
Observe the above table and answer the following questions.

1. Which crop is most suitable to cultivate for small farmer in both the villages?
Answer:
Cotton, paddy

2. If you are a large farmer, which crop do you select to cultivate?
Answer:
Cotton, paddy, mirchi

3. What similarities you have identified in village A and village B?
Answer:
Small and large fanners cultivated same type of crop in both villages. Large farmer gets more income per acre on crops than small farmer in both the villages.

4. Which is the lowest income crop ?
Answer:
Mirchi.

5. Is there any relationship between production of crops and income ? How ?
Answer:
Commercial crops are good for income. Income may or may not related to production of crop. It depends upon demand of the market.

Question 7.
Read the given information and answer the following questions.

A survey was conducted in two villages, Vanaparthy and Vaddicherla of Warangal district in Telangana State. The first with no scarcity and the second with scarce groundwater. Well census was carried out in the villages in order to get a complete picture of well irrigation and its status as well as availability of water. There are no alternative sources of supply as against wells in Vaddicherla, where there is an existing tank that has been converted into a percolation tank, so that the water situation is much better in Vanaparthy.

i) Why did they conduct survey?
Answer:
A compartive study on available water resources irigation method in the Vaddicharla and Wanaparthi of Warangal Dist of Telangana State.

ii) What are irrigation resources in Telangana State?
Answer:
Lakes, wells, canals and ground water etc…,

iii) In which village, do you suggest drip irrigation?
Answer:
Vaddicherla.

iv) Why the water situation is much better in Vanaparthy village compared to Vaddicherla?
Answer:
Existing tank has been converted into a percolation tank.

Question 8.
Observe the Pie diagram and answer the following questions.
i) Identify the fossil fuels from the above diagram.
Answer:
Coal, natural gas, oils are fossil fuels.

ii) Why wastes should be considered as primary energy source in future?
Answer:
The fossil fuels may be exhausted in future. So we may be considered that wastes are primary alternative energy resources.

iii) Why can’t we depend on fossil fuels forever?
Answer:
We can’t depend on fossil fuels forever because fossil fuels are non-renewable resources.

iv) What are the alternatives for fossil fuels?
Answer:
Solar energy, wind energy, tide energy, nuclear energy, energy from waste materials.

Question 9.
Explain the importance and implementation of community based interventions and farmer based interventions for water management.
Answer:
Community based interventions:

1. For water harvesting, there is an urgent need to construct earthen and masonry dams. They help us to store rain water during rainy seasons. They are help in increasing the ground water table.
2. Construction of percolation pits and field bunding are very helpful in the harvesting every rain drop.
3. Open dry wells near nalla canal were recharged by building dykes or barriers in the nalla and maintaining the run – off rain water. The ground water is recharged by these community based interventions.
   Farmer based interventions:
4. Broad Bed Furrow (BBF) land form and contour planting methods are very useful to conserve soil, water and fertilizer application and weeding operations.
5. Planting Gliricidia, a leguminous plant adapted to grow in dry areas on field bunds to strengthen them and make the soil nitrogen rich.
6. Farmers were encouraged to use water resource jointly and irrigate land using micro irrigation methods like sprinklers and drip irrigation.

Question 10.
Explain the farmer based and community based interventions to conserve soil and water resources.
Answer:

Question 11.
“The humans who were developed by using the natural resources, today has become the reason for destroying them”. Explain analytically.
Answer:
“The humans who were developed by using the natural resources, today has become the reason for destroying them” – This statement is absolutely true.

1. Primitive man lived in forests and hills. He used the natural resources for his livelyhood. He worshipped nature and used them wisely for his development.
2. After his development, he becomes greedy and using the natural resources indiscriminately and held responsible for their destruction.
3. To meet the needs of growing population, industrialization, urbanization, and huge constructive activities, man utilised natural resources Indiscriminately. At the same time, he did not planned for their revival.
4. But now he realised the importance of natural resources and taken up steps for their conservation. The concept of “Sustainable development” is being implemented in natural resource management.
5. He focussed on development of alternatives for fossil fuels, conservation of water and soil at community level and farmer based interventions.
6. Now he is so keen on conserving forests, wild life and biodiversity.
7. He is so cautious in minimising the utilization of natural resources by following 4’R principle in the day to day life [R – Reduce, R – Reuse, R – Recycle, R – Recover]
8. Now, he is adopting micro-irrigation methods like sprinklers and drip Irrigation to minimise the water usage in low water available areas.
9. He is very interested in following eco-friendly techniques, natural farming methods, using biofertilizers, vermicompost and natural pest control methods in place of toxic chemical pesticides.

Question 12.
The wells and tanks in your village become dry. Ground water levels decreased. Assume the causes for this. Will there be no water scarcity if all the farmers of your village work collectively?
Answer:
Causes for decreasing ground water levels:

1. Varying monsoon behaviour in recent years, there is a pressure on ground water utilization.
2. Indiscriminate tapping of ground water in our village by too much drilling and construction of deep tube wells and bore wells have resulted in over exploitation and depletion of ground water resources.
3. There will be no water scarcity if all the farmers of our village work collectively. Farmers in our village were encouraged to use water resource jointly and irrigate land using micro irrigation techniques. By using micro irrigation techniques farmers in our village obtained more crop yield. Farmers in our village follow the micro irrigation method i.e. drip irrigation and can reduce water consumption by 70% in our village.

Question 13.
Whom do you meet to collect the information of the methods of farmer based, community based water management? Prepare information table to note down your observation.
Answer:
I will meet officials of International Crop Research Institute for Semi – Arid Tropics (ICRISAT) located at Hyderabad to collect information of the methods of farmer based and community based water management.
I also collect information from Central Research Institute for Dry Land Agriculture (CRIDA), National Remote Sensing Agency (NRSA), District Water Management Agency (DWMA) and M Venkatarangaiah Foundation (MVF) and NGO.
The information I gathered from these institutions is summarised below.
Information table:
For Information table See Q.No. 10 in 4 Marks.

Question 14.
Think that there is much scarcity of water for drinking and cultivation in your village. What advice do you give to prevent this?
(OR)
How do you overcome the problem of water scarcity in your village?
Answer:

1. Motivate the people to conserve water.
2. I will educate the people to avoid wastage of water whenever possible.
3. Construction of recharge pits in the house, school and in the open areas to increase the underground water level.
4. Planting trees wherever possible in the village particularly in the vacant lands.
5. Educate the farmers about the micro irrigation system like drip irrigation, sprin¬klers, etc.
6. Encourage the farmers to form groups to share available water among themselves.
7. Construction of percolation tanks in the low lying areas of the village.

Question 15.
What type of fossil fuels are used in your house? What measures do you take to conserve them?
Answer:
Fossil fuels are sources of energy for cooking, heating and burning in our households. Petrol and diesel are being used in our house for transport and running generators and water pumps.
Measures to be taken to conserve fossil fuels in my house :

1. I will put the food material to be cooked on the stove only after arranging all the things which are necessary for cooking.
2. By using pressure cookers 20% gas on rice and 41.5% on meat would be saved when compared to Other cooking means.
3. We must reduce the flame as soon as the boiling process starts in a pressure cooker. This process saves nearly 35% of fuel.
4. I will soak the food material before cooking. It saves 22% of fuel.
5. I will cook food in broad and low depth vessel.
6. I will keep lid on the cooking vessel. If not, it takes more time to cook.
7. For short distances to travel I will go by walk to save fuel for longer distance. I use public transport.
8. Encourage people to use solar water heater and solar cooker.

AP State Board Syllabus AP SSC 10th Class Biology Solutions Chapter 1 Nutrition – Food Supplying System Textbook Questions and Answers.

AP State Syllabus SSC 10th Class Biology Solutions 1st Lesson Nutrition – Food Supplying System

10th Class Biology 1st Lesson Nutrition – Food Supplying System Textbook Questions and Answers

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Question 1.
Write differences between
(a) Autotrophic nutrition – Heterotrophic nutrition:
Answer:

(b) Ingestion – Digestion :
Answer:

(c) Light reaction – Dark reaction :
(OR)
Differentiate the reactions that take place in presence of light and the reactions which do not require light in photosynthesis.
Answer:

(d) Chlorophyll – Chloroplast:
Answer:

Question 2.
Give reasons.
a) Why photosynthesis is considered as the basic energy source for most of living world?
(OR)
Why can we say that photosynthesis is the basic energy source for the living world?
Answer:

1. All living organisms constantly need energy to be alive.
2. They get energy from the food they eat.
3. The food directly or indirectly comes from the green plants through photosynthesis.
4. Hence photosynthesis can be considered as the basic energy source for most of living world.

b) Why is it better to call the dark phase of photosynthesis as a light independent phase?
Answer:

1. The term dark reaction or light independent does not mean that they occur when it is dark at night.
2. It only means that the reactions are not depend on light.
3. Hence we call the dark phase of photosynthesis as a light independent phase.

c) Why is it necessary to destarch a plant before performing any experiment on photosynthesis?
Answer:
1) To get better results, it is necessary to destarch a plant before performing any experiment on photosynthesis.
2) Because if starch is present it may interfere with the result of the experiment.

d) Why is it not possible to demonstrate respiration in green plants kept in sunlight?
Answer:

1. We cannot demonstrate an experiment of respiration in green plants kept in sunlight.
2. Because if sunlight is present, the C02 produced in respiration will be used in photosynthesis.
3. So we must conduct an experiment on respiration in green plants in a dark room.

Question 3.
Give examples.
a) Digestive enzymes
Answer:
The digestive enzymes are:

1. Salivary Amylase (Ptyalin),
2. Pepsin,
3. Trypsin,
4. Lipase,
5. Peptidases,
6. Sucrase,
7. Amylase (Pancreatic juice)

b) Organisms having heterotrophic nutrition is seen in organisms like:
Answer:
Heterotrophic nutrition is seen in organisms like:

1. All animals and human beings.
2. Some protozoans Ex: Amoeba.
3. Some parasitic plants Ex: Cuscuta
4. Saprophytes Ex: Bread moulds, yeast, mushrooms, etc.

c) Vitamins
Answer:
Water soluble vitamins:
B complex (B₁) Thiamine, (B₂) Riboflavin, (B₃) Niacin, (B₆) Pyridoxine,
(B₁₂) Cyanocobalamine, Folic acid, Pantothenic acid, Biotin, (C) Ascorbic Acid.
Fat soluble: (A) Retinol, (D) Calciferol, (E) Tocoferol, (K) Phylloquinine.

d) Nutritional deficiency diseases
Answer:
Eg: Kwashiorkor, Marasmus etc.

Question 4.
Where do plants get each of the raw materials required for photosynthesis?
Answer:

Question 5.
Explain the necessary conditions for autotrophic nutrition and what are its by products.
Answer:
A. Necessary conditions:

1. Autotrophic nutrition takes place through the process of photosynthesis.
2. Carbon dioxide, water, chlorophyll pigment and sunlight are the necessary conditions required for autotrophic nutrition.
3. The rate of photosynthesis depends on availability of sunlight.

B. By products:

1. Photosynthesis is the main process for autotrophic nutrition.
2. Carbohydrates and oxygen are the by products of photosynthesis.

Question 6.
With the help of chemical equation explain the process of photosynthesis In detail with the help of a flow chart.
Answer:
Process of photosynthesis:

1. The chemical equation representing the process of photosynthesis is
   
2. Definition: Photosynthesis is a photochemical reaction during carbohydrates are formed using carbon dioxide and water in the chloroplasts of the green plants in the presence of sunlight.
3. CO₂ water, sunlight and chlorophyll are the requirements of photosynthesis.
4. Glucose, O and water are the end products of the reaction.
5. Photosynthesis have two phases.
   1) Light reaction 2) Dark reaction
6. Light reaction have three steps, i) Oxidation of chlorophyll ii) Photolysis iii) Formation of ATP, NADPH and O₂
7. In dark reaction CO₂ is utilized and finally glucose is formed which is converted and stored as starch.

FLOW CHART:

Question 7.
Name the three end products of photosynthesis.
Answer:
Glucose, oxygen and water are the three end products of photosynthesis.

Question 8.
What is the connecting substance between light reaction and dark reaction?
Answer:
The hydrogen of NADPH present in the stroma is the connecting substance between light reaction and dark reaction.

Question 9.
Most leaves have the upper surface is more green and shiny than the lower ones. Why?
(OR)
In most of leaves the upper surface will be more green and shiny than the lower surface. Why?
Answer:

1. The upper surface comprising of the palisade parenchyma.
2. The lower surface comprising of the spongy parenchyma.
3. Palisade parenchyma contains more number of chloroplasts than the spongy parenchyma.
4. Thus the upper surface is more green and shiny than the lower ones.

Question 10.
Explain the structure of chloroplast with a neatly labelled sketch.
(OR)
Explain the structure of a chloroplast with the help of a rough diagram.
Answer:

1. Chloroplast is a membranous structure consisting of 3 membranes.
2. The third layer forms stacked sac like structures called granum.
3. The intermediatery fluid filled colourless portion is called stroma.
4. It is responsible for enzymatic reaction leading to the synthesis of glucose in plants.
5. Substances found in chloroplast, capture sunlight are called photosynthetic pigments.
6. Chlorophyll pigment contain one atom of magnesium.
7. Two major kinds of chlorophylls are associated with thyakoid membranes.
8. Chlorophyll-a is blue-green in colour and chlorophyll-b is yellow-green colour.
9.  Around 250-400 pigments molecules are grouped as light harvesting complex units in granum.
10. Some of the events occur in chloroplast are :
    a) Conversion of light energy to chemical energy.
    b) Splitting of water molecule.
    c) Reduction of carbondioxide to carbohydrates.

Question 11.
What is the role of acid in stomach?
Answer:

1. The internal walls of stomach has number of gastric glands. They secret gastric juice.
2. It contains HCl and enzymes.
3. HCl kills the bacteria present in the food and protects us from their harmful effects.
4. And also denatures the proteins so that enzymes can act easily on them.

Question 12.
What is the function of digestive enzyme?
Answer:

1. The function of digestive enzyme is to increase the process of breaking up of complex molecules into simpler and absorb molecules.
2. This makes easy for the body to absorb food.

Question 13.
How is the small intestine designed to absorb digested food? Explain.
(OR)
How is food absorbed by villi in small intestine?
Answer:

1. Small intestine is the largest part in digestive system.
2. Absorption is its main function including last stage of digestion.
3. The inner surface of small intestine has millions of tiny finger-like projections called villi.
4. Due to the presence of villi, the absorbing surface area of small intestine increases.
5. And the large surface area of small intestine helps in the rapid absorption of digested food.
6. The digested food which is absorbed through the walls of the small intestine goes into our blood.
7. Long and folding structure increase the ability of small intestine.

Question 14.
How are fats digested in our bodies? Where does this process take place?
What is emulsification? How it helps in digestion of fats? (OR)
How are fats digested? Where do they get digested?
Answer:

1. Bile juice and lipase enzymes helps in fat digestion.
2. Bile juice is secreted by liver.
3. Fats are digested by converting them into small globules like forms by the help of the bile juice.
4. This process is called emulsification.
5. Lipase enzyme is secreted by pancreas.
6. It converts emulsified fats into fatty acids and glycerol.
7. 
8. This process takes place in duodenum and small intestine.

Question 15.
What is the role of saliva in the digestion of food ?
(OR)
How does saliva digest food ?
Answer:

1. Saliva is secreted by three pairs of salivary glands present in the mouth.
2. Human saliva contains an enzyme called amylase (ptyalin).
3. It converts starch into maltose (a sugar).
4. The food is mixed thoroughly with saliva and becomes wet and slippery.
5. Saliva helps in the smooth passage of food in the food pipe.

Question 16.
What will happen to protein digestion as the medium of intestine is gradually rendered alkaline ?
Answer:

1. The food coming from the stomach to intestine is acidic in nature.
2. Bile and pancreatic juices render the internal condition of the intestine gradually to a basic or alkaline one.
3. Protein digestion continues even if the medium of intestine is gradually changed to alkaline.
4. In the alkaline medium pancreatic enzyme trypsin can act on the food and digests the proteins.
   
5. The enzymes present in the intestinal juice like peptidases complete the digestion of proteins into amino acids.
   

Question 17.
What is the role of roughages in the alimentary tract?
Answer:

1. Roughages are the fibres of either carbohydrates or proteins.
2. Plenty of roughages in the diet avoid constipation.
3. Roughages help in the easy movement of faeces in the large intestine.
4. They help in the easy digestion of food and keep the alimentary canal clean and healthy.

Question 18.
What is malnutrition? Explain some nutrition deficiency diseases.
Answer:
Malnutrition: Eating of food that does not have one or more than one nutrients in required amount is known as malnutrition.
Malnutrition is of three types:

1. Calorie malnutrition,
2. Protein malnutrition,
3. Protein calorie malnutrition.

Nutrition deficiency diseases:

1. Kwashiorkor disease: This is due to protein deficiency in diet.
   Symptoms:
   i) Body parts becomes swollen due to accumulation of water in the intercellular spaces,
   ii) Very poor muscle development,
   iii) Swollen legs,
   iv) Fluffy face,
   v) difficult to eat,
   vi) diarrhoea,
   vii) Dry skin.
2. Marasmus: This is due to deficiency of both protein and calories. Generally this disease occurs when there is an immediate pregnancy or repeated child births.
   Symptoms:
   i) Lean and weak,
   ii) Swelling in joints of limbs,
   iii) Less developed muscles,
   iv) Dry skin,
   v) diarrhoea.

Question 19.
How do non-green plants such as fungi and bacteria obtain their nourishment?
Answer:

1. Bacteria and fungi are non-green plants. So they cannot prepare their own food materials.
2. They are saprophytes which feed on dead and decaying plant and animal bodies.
3. The fungi and bacteria breakdown the complex organic molecules present in dead and decaying matter by releasing chemical substances into simple substances out¬side the body.
4. These simpler substances are then absorbed by fungi and bacteria as their food.

Question 20.
If we keep on increasing CO₂ concentration in the air, what will be the rate of photosynthesis?
Answer:

1. If the CO₂ concentration in the air increases, the rate of photosynthesis also increases.
2. If the CO₂ concentration raises above 5% then the rate of photosynthesis reduces.
3. At certain CO₂ concentration the rate of photosynthesis is constant.
4. Here a rise in CO₂ levels has no affect on the rate of photosynthesis as the other factors such as light intensity become limited.

Question 21.
What happens to plant if the rate of respiration becomes more than the rate of photosynthesis ?
Answer:

1. Respiration is a catabolic (destructive) process and photosynthesis is an anabolic (constructive) process.
2. If the rate of respiration becomes more than the rate of photosynthesis, the amount of food oxidised will be more than the food produced.
3. This affects the growth and development of plants and may even results in the death of the plant.

Question 22.
Why do you think that carbohydrates are not digested in the stomach?
(OR)
Where are carbohydrates digested in alimentary canal?
Answer:

1. For the digestion of carbohydrates enzyme ptyalin or amylase are required.
2. The gastric juice produced by stomach do not contain the enzyme ptyalin or amylase, it contains only pepsin which digests proteins.
3. Hence carbohydrates are not digested in the stomach.
4. Carbohydrates are partially digested in the mouth and completely in small intestine.

Question 23.
What process do you follow in your laboratory to study the presence of starch in leaves?
(OR)
(Activity – 1)
How do you test the presence of starch in leaves ? (OR)
Mention the materials required and explain the experiment to prove the presence of starch in leaves. What inference do you draw from this experiment?
Answer:
Aim: To study the presence of starch in leaves.
Apparatus: Beaker, test tube, bunsen burner, tripod stand, asbestos gauze, ethanol, leaf, petridish, iodine solution.
Procedure:

1. Select a leaf of a potted plant with soft thin leaves.
2. Boil the leaf in methylated spirit over a water bath till it becomes pale white due to the removal of chlorophyll.
3. Observe the leaf.
   
4. Spread the leaf in a dish and add a few drops of tincture iodine / betadine solution on it. Again observe the leaf.

Observation: The presence of starch will be indicated by a blue-black colour in leaf. Result: The experiment proves that starch is present in leaves. It is formed by Photo-synthesis.
Precautions:

1. Do not boil the methylated spirit test tube directly on flame.
2. Boil the water bath with low flame.

Question 24.
How would you demonstrate that green plants release oxygen when exposed to light? (OR) (Lab Activity)
Write the experimental procedure to prove that oxygen is produced during photosynthesis in the presence of light. (OR)
What materials are required to prove that oxygen is produced during photosynthesis in the presence of light? What procedure we need to follow to perform the above experiment?
We have conducted experiment that prove the release of oxygen when photosynthesis happens?
i) What are the plants used for this experiment? Where do they grow?
ii) How did you conduct the above experiment? In which context large number of air bubbles released? Do you noticed?
Answer:
i) Hydrilla plants are used for this experiment they grow in water.
ii) Experiment to demonstrate the release of oxygen during photosynthesis.
Aim: To prove that oxygen is produced during photosynthesis by hydrilla funnel experiment.
Apparatus: Beaker with water, test tube, funnel, hydrilla twigs, glowing splinter.
Procedure:

1. Arrange the apparatus as shown in the figure.
2. Place some water plant hydrilla in a beaker containing pond water, and cover these by a short stemmed funnel.
3. Invert a test – tube full of water over the stem of the funnel.
4. Ensure that the level of water in the beaker is above the level of stem of the inverted funnel.
5. Place the apparatus in the sun for at least 2 or 3 hours.
6. After sometime it is observed that gas bubbles come from the hydrilla plant. These bubbles are collected at the end of the test tube pushing the water into the beaker.
7. After sufficient gas is collected test – tube is taken out of the beaker carefully by closing it with thumb.

Observation: Test the gas in the test – tube by inserting a glowing incense stick which would burst into flames. This shows the presence of oxygen.
Result: This shows that oxygen is produced during photosynthesis.
Precautions:

1. Funnel should be smaller than the beaker.
2. Necessary care is to be taken while removing the test tube from the stem of the funnel.

Question 25.
Collect information from your primary health centre of malnutrition child at various ages and make a table your own and display in the classroom.
Answer:

Question 26.
If there were no green plants, all life on the earth would come to an end ! Comment.
(OR)
The survival of organisms would become difficult, if there are no green plants on the earth. How do you support?
Answer:

1. Plants play the most important part in the cycle of nature.
2. Without plants there could be no life on earth.
3. Plants are the only organisms that can make their own food and all other living beings directly or indirectly depend on plants for their food.
4. Moreover plants release oxygen into the atmosphere through photosynthesis.
5. Oxygen is essential for the organisms to respire.
6. Hence without green plants, all life on the earth would come to an end.

Question 27.
Draw a neat labelled diagram of chloroplast found in leaf, and its role in photosynthesis.
Answer:
Role of Chloroplast in photosynthesis:

1. Chloroplasts trap solar energy.
2. They convert that solar energy into chemical energy.
3. They help in the formation of glucose.

Question 28.
Draw the label diagram of human digestive system. List out the parts where peristalsis takes place.
Answer:
Parts where peristalsis takes place: Oesophagus, stomach, small intestine and large intestine.

Question 29.
Raheem prepared a model showing the passage of the food through different parts of the alimentary canal. Observe this and label its parts.
Answer:

Question 30.
Observe the following diagram and write a note on light dependent, light independent reactions.
Answer:
Note on light dependent reactions:

1. Light dependent reactions are also called as photochemical phase.
2. The light dependent reaction takes place in chlorophyll containing thylakoids called grana of chloroplasts.
3. Several steps occur in the light dependent reaction.
4. Step – 1: The chlorophyll on exposure to light energy becomes activated by absorbing photons.
5. Step – II: The energy is used in splitting the water molecule into two component ions named hydrogen (H⁺), hydroxyl ion (OH^–). This reaction is known as photolysis.
6. Step – III: OH^– ions through a series of steps produce water (H₂O) and O₂.
7. The end products of light reaction are ATP, NADPH and O₂.

Note on dark reaction or light independent reaction:

1. In light independent phase the hydrogen of the NADPH is used to combine it with CO₂, by utilizing ATP energy and to produce glucose.
2. This synthesis occurs in a number of steps using certain special intermediate compounds (mainly RUBP – Ribulose hi phosphate) and enzymes. Finally glucose is converted to starch.
3. All these reactions occur in the stroma region of the chloroplast.

Question 31.
Almost all the living world depends on plants for food material. How do you appreciate the process of making food by the green plants?
(OR)
What facts about the green plants do you appreciate?
Answer:
Leaf is a wonderful machine to synthesize food:

1. The leaf is the important site of photosynthesis and is called as food factory of the plant.
2. This plant organ can be treated as a wonderful natural machine which converts solar energy into useful chemical energy.
3. With all his scientific knowledge and technical skills, man has not produced anything similar leaf for utilization of solar energy without polluting the atmosphere.
4. This machine provides food and supports the life by providing oxygen for all the organisms including man on this planet.
5. Nature has given us such a wonderful machine free !!

Question 32.
Even a hard solid food also becomes smooth slurry in the digestive system by the enzymes released at a particular time. This mechanism is an amazing fact. Prepare a cartoon on it.
Answer:

Question 33.
What are good food habits?
Answer:
The food habits I am going to follow after reading this chapter are:

1. I take balanced diet which contains proper amounts of carbohydrates, proteins, fats, vitamins and minerals.
2. I avoid taking food containing high proportion of fat.
3. I eat food as much required by my body. I do not over eat.
4. I will not eat rich meals over several days.
5. I eat simple balanced meals, eat it leisurely and thoroughly masticating the food.
6. I avoid doing violent exercise soon after eating food.
7. I empty the bowels regularly avoiding constipation.
8. I will see to have plenty of roughages in the diet.

(OR)
After reading the chapter nutrition, I would like to follow the following food habits.

1. Having simple, well balanced meals.
2. Eating them in a leisurely manner.
3. Thoroughly masticating the food.
4. Avoiding strenuous exercise soon after eating food.
5. Drinking plenty of water and having regular bowel movement.
6. Decreasing consumption of coffee or tea per day.
7. Taking leafy vegetables at least 3 times a week and taking of fruits and vegetables plenty.
8. Maintaining regular timings for daily food consumption.

Fill in the blanks.

1. The food synthesized by the plant is stored as ———–.
2. ———– are the sites of photosynthesis.
3. Pancreatic juice contains enzymes for carrying the process of digestion of ———– and ———–.
4. The finger-like projections which increases the surface area in small intestine are called ———–.
5. The gastric juice contains ———– acid.
6. ———– vitamin is synthesized by bacteria present in intestine.

Answer:

1. carbohydrates
2. Chloroplasts
3. proteins, fats
4. Villi
5. HCl
6. Cyanocobalamin

Choose the correct answer.

1. Which of the following plant take the food by parasitic nutrition? [ ]
   A) Yeast
   B) Mushrooms
   C) Cuscuta
   D) Leeches
   Answer: C & D
2. The rate of photosynthesis is not affected by [ ]
   A) Light intensity
   B) Humidity
   C) Temperature
   D) Carbon dioxide concentration
   Answer: B
3. A plant is kept in dark cupboard for about forty eight hours before conducting any experiment on photosynthesis in order to [ ]
   A) Remove chlorophyll from leaves
   B) Remove starch from leaves
   C) Ensure that no photosynthesis occurred
   D) Ensure that leaves are free from the starch
   Answer: B
4. The digestive juice without enzyme is [ ]
   A) Bile
   B) Gastric juice
   C) Pancreatic juice
   D) Saliva
   Answer: A
5. In single-celled animals, the food is taken by [ ]
   A) the entire body surface
   B) mouth
   C) teeth
   D) vacuoles
   Answer: A
6. Which part of the plant takes in carbon dioxide from the air for photosynthesis? [ ]
   A) Root hair
   B) Stomata
   C) Leaf veins
   D) Sepals
   Answer: B

10th Class Biology 1st Lesson Nutrition – Food Supplying System Activities

Activity – 1

How do you prove experimentally that carbon dioxide is necessary for photosynthesis by Mohl’s half leaf experiment?
(OR)
List out the materials required and the procedure to be followed to prove that ‘carbon dioxide’ is essential for photosynthesis.
(OR)
You know that the factors like CO₂, Light and Chlorophyll are essential for photosynthesis. Write any one of experiment related to the factors essential for photosynthesis.
Answer:
Aim:
To prove-that carbon dioxide is essential for photosynthesis by Mohl’s half leaf experiment.
Apparatus:
Wide mouthed transparent bottle, KOH solution, potted plant, vertically split cork, Iodine solution.
Procedure:
Arrange the apparatus as shown in the figure.

1. Take a healthy potted plant and keep it in the dark for nearly a week for the removal of starch from the leaves.
2. A wide mouthed transparent bottle is taken.
3. Put potassium hydroxide pellets or potassium hydroxide solution (KOH) in the bottle.
4. This KOH absorbs CO₂ present in the bottle.
5. Insert splitted cork in the mouth of the bottle.
6. Insert one of the leaves of destarched plant through a split cork into transparent bottle.
7. Arrange half of the leaf is inside bottle and the remaining half outside.
8. Leave the plant in the sunlight for 2-3 hours.
9. After a few hours, test this leaf and other leaf of this plant for starch.

Observation :

1. The part of the leaf outside the bottle turns blue-black because starch is formed in this part due to photosynthesis.
2. The part of the leaf inside the bottle does not turn blue-black because the carbon dioxide present inside the bottle is absorbed by potassium hydroxide solution.
3. All the other factors water, sunlight and chlorophyll are available but not CO₂. Hence starch is not formed in the leaf part which is inside the bottle.

Result: This experiment proves that CO₂ is necessary for photosynthesis. Precautions:

1. The part of the leaf kept inside the bottle should not touch potassium hydroxide solution.
2. The apparatus should be kept air tight by applying grease or vaseline.

Activity – 2

Sunlight is necessary to form starch in green leaves.
(OR)
Write the materials required and the procedure to prove that light is essential for Photosynthesis.
(OR)
Write the procedure, precautions and observations in the lab activity, “Sunlight is necessary for photosynthesis”.
Answer:
Aim:
To prove that light is necessary for photosynthesis to form starch.
Apparatus:
Potted plant, light screen, iodine solution.

1. Keep potted plant in dark for one week to remove starch.
2. Take one black paper and cut it with your own design.
3. Keep design paper properly on the both sides with the help of clips.
4. Ensure that light does not pass through the covered area with black paper.
5. Keep the arranged apparatus at sunlight available area.
6. After few hours of exposure to bright sunlight detach the leaf.
7. Boil the leaf in methylated spirit over water bath. It becomes pale white due to the removal of chlorophyll. Take the leaf from test tube and spread the leaf in a petridish.
8. Add few drops of Iodine on leaf. The parts of the leaf, which could get light through the cut out design, turns blue-black colour.
9. The parts of the leaf which could not get light are not turned into blue – black colour.
   

Observation:
It is observed that only the parts of the leaf, which could get light through the cut out design, turn blue black, showing the presence of starch.

Result:
This experiment proves that light is necessary to form starch in the process of photosynthesis.

Activity – 3

Demonstrate litmus paper test on salivary amylase in the mouth.
Answer:

1. Before taking food into the mouth, take a litmus indicator paper and touch it to the tongue.
2. We observe no colour change in litmus paper.
3. Perform the litmus test again after chewing the food and swallowing it.
4. The red litmus paper turns to blue colour.
5. The blue litmus paper do not turns to red colour.
6. This demonstrates that amylase converts complex carbohydrates to simple sugar.
7. Amylase is alkaline in nature. This turns litmus paper blue when touches glucose at the second time.
   

Activity – 4

Observe different digestive enzymes and their role in digesting food in a tabular form.
Answer:

10th Class Biology 1st Lesson Nutrition – Food Supplying System InText Questions and Answers

10th Class Biology Textbook Page No. 2

Question 1.
Can you think of some raw materials needed for photosynthesis?
Answer:
Yes. Photosynthesis needs the following raw materials.

1. Sunlight, CO₂ water are external factors.
2. Chlorophyll and enzymes are internal factors.

Question 2.
What could be the end products of the process of photosynthesis?
Answer:
Glucose, water and oxygen are the end products of photosynthesis.

10th Class Biology Textbook Page No. 4

Question 3.
Do you think solar energy transforms into chemical energy by the process of photosynthesis?
Answer:
Yes, solar energy transforms into chemical energy by the process of photosynthesis.

Question 4.
What are the materials that you think would be essential for the synthesis of carbohydrates in the process of photosynthesis?
Answer:
The materials essential for the synthesis of carbohydrates in the process of photosynthesis are carbon dioxide, water, sunlight and chlorophyll.

Question 5.
Do you think the equation tells us about all the materials involved?
Answer:
Yes, the materials which are essential for photosynthesis and the products formed are involved in the equation.

10th Class Biology Textbook Page No. 5

Question 6.
What had Priestly done to introduce the mint plant without disturbing the experimental setup?
Answer:
Priestly should have tilted the bell jar to one side and introduced the mint plant without disturbing the experimental set up.

Question 7.
How did Priestly light the candle from outside?
Answer:
Priestly might have used convex lens through which beam of sun rays can light the candle from outside or he might have used long burning stick, to light the candle by lifting the jar partially.

Question 8.
Do you find any relationship between candle, rat, mint plant? Discuss.
Answer:
Priestly’s experiment confirmed that gaseous exchange was going on and plants were giving out a gas that supported burning and was essential for the survival of animals.
By combustion process candle releases carbondioxide. By respiration process rat also releases carbondioxide. During photosynthesis process mint plant uses this carbondioxide and releases oxygen. This oxygen will be used by rat to stay alive and for the candle to burn.
So there is a relationship between respiration and photosynthesis by candle, rat and mint plant.

10th Class Biology Textbook Page No. 6

Question 9.
Why was the plant kept in dark and then in sunlight?
Answer:

1. The plant is kept in the dark for nearly a week to remove the starch from the leaves.
2. Then only we can understand that the starch is formed in the leaves or not after the experiment when the plant is kept in the sunlight.

Question 10.
Why did we study two leaves in the Mohl’s half leaf experiment?
Answer:

1. To test CO₂ is essential or not for photosynthesis, two leaves are used in the experiment.
2. One leaf with the plant and another one used in the experiment.
3. The leaf which is exposed to the atmospheric air becomes bluish-black. It proves that starch is prepared in the leaf by using CO₂ from atmosphere.
4. The leaf inside the flask containing potassium hydroxide, which absorbs CO₂ present in the bottle does not become bluish black. It shows that CO₂ is necessary for photosynthesis.

10th Class Biology Textbook Page No. 7

Question 11.
What precautions do you need while removing test tube from the beaker? Discuss with your teacher.
Answer:

1. When sufficient gas is collected lift the test tube carefully from the beaker by closing its mouth with the thumb.
2. Because of that the gas present in the test tube cannot escape into the atmosphere.

10th Class Biology Textbook Page No. 8

Question 12.
Which part of leaf turns blue black? What about the remaining part?
Answer:

1. The part of the leaf, which could get light through the cut design turns to blue black showing the presence of starch.
2. The remaining part of the leaf which did not get light, do not turn blue, indicating that starch is not prepared.

Question 13.
Observe the colour of the leaf stained with iodine. Can you tell why it is stained differently?
Answer:

1. Some parts of the leaf prepared starch.
2. Some parts of the leaf does not prepared starch.
3. So it is stained differently.

Question 14.
What about plants having coloured leaves?
Answer:
Plants having coloured leaves also carry out photosynthesis. The coloured leaves containing pigments pass on the energy of sunlight trapped by them to chlorophyll.

Question 15.
How is that new leaves which look dark red in colour in several plants turn green?
Answer:

1. The new leaves which look dark red in colour contain coloured chromoplasts.
2. As the leaf grows the chromoplasts turns to chloroplasts and the leaf appears green in colour.

Question 16.
Do plants having reddish or yellowish leaves also carry out photosynthesis?
Answer:

1. Yes. Plants having reddish or yellowish leaves also carry out photosynthesis.
2. The pigments present in reddish or yellowish leaves pass on the energy of sunlight trapped by them to chlorophyll.

Question 17.
What made plants carry out photosynthesis while even green coloured animals (like some birds) could not?
Answer:

1. Chlorophyll and other pigment molecules trap (harvest) solar energy, convert it into chemical energy in the thylakoid membranes of the chloroplast.
2. But animals having green colour on their body cannot trap solar energy and cannot perform photosynthesis. Photosynthesis is possible only in plants but not in animals.

10th Class Biology Textbook Page No. 9

Question 18.
Where is chlorophyll and other pigments present in the plant?
Answer:
Chlorophyll and other pigments are present in the grana thylakoids of chloroplast in leaf.

Question 19.
Do you think the new reddish leaves of plants also carry out photosynthesis? What could be the role of their colour?
Answer:

1. Yes. New reddish leaves of plants also carry out photosynthesis.
2. Chromoplasts are responsible for the reddish colour of leaves.
3. They also pass on the energy of sunlight which they trap to the photosystems.

10th Class Biology Textbook Page No. 10

Question 20.
What makes chloroplast appear completely different from other cell organelles?
Answer:

1. Substances found in chloroplast, which capture sunlight are called photosynthetic pigments.
2. Two major kinds of chlorophyll are associated with thylakoid membranes.
3. Chlorophyll – a (blue – green in colour) and chlorophyll – b (yellow – green); around 250 to 400 pigment molecules are grouped as light harvesting units in each granum.
4. Such innumerable units in chloroplasts make them appear completely different from other organelles.

10th Class Biology Textbook Page No. 13

Question 21.
What happens to the food once it enters our body?
Answer:

1. The food once enters our body it gets digested by various enzymes in different parts of alimentary canal.
2. Digestion starts in the mouth and it completes in the small intestine.
3. Finally it absorbed in the small intestine into the circulatory system.

10th Class Biology Textbook Page No. 15

Question 22.
Name the enzymes which act on carbohydrates.
Answer:
Ptyalin (salivary amylase), amylase and sucrose are the enzymes that act on carbohydrates.

10th Class Biology Textbook Page No. 16

Question 23.
What are the end products of fats?
Answer:
The end products of fats are fatty acids and glycerol.

Question 24.
What are the enzymes that act on proteins?
Answer:
Pepsin, Trypsin and Peptidases are the enzymes that act on proteins.

Question 25.
Which digestive juice contains no enzymes?
Answer:
Bile juice produced by liver contains no enzymes.

Question 26.
What do you think about the process of digestion?
Answer:

1. The process of digestion occurs in the alimentary canal or digestive system.
2. During the process of digestion large complex macro molecules present in the food are converted to simple and small molecules.
3. Digestion provides the food material properly absorbed by the body.

Question 27.
What are the major steps of digestion?
Answer:
The major steps of digestion are

1. Ingestion
2. Digestion
3. Absorption and
4. Defecation.

10th Class Biology Textbook Page No. 18

Question 28.
Collect information about pellagra and discuss with your teacher.
Answer:

1. Pellagra is a vitamin-deficient disease.
2. Niacin (Vitamin – B₃) is essential for the metabolism of carbohydrates, proteins and fats.
3. The resources for vitamin – B₃ are kidney, liver, meat, egg, fish, oil seeds and legumes.
4. Deficiency of niacin results in a disease called PELLAGRA.

Symptoms: Pellagra is described by 3 Ds – Diarrhoea, Dermatitis, Dementia.
A more comprehensive list of symptoms include

1. Sensitivity to sunlight
2. Aggression
3. Dermatitis
4. Alopecia (hair loss)
5. Edema (swelling)

Smooth, beefy red, glossitis, red skin lesions, insomnia (sleepless), weakness, mental confusion, nerve damage are the symptoms of this pellagra.

Prevention: By taking of yeast, meat, fish, milk, eggs, green vegetables, beans and cereal grains, we can prevent this disease.

AP State Board Syllabus AP SSC 10th Class Physics Solutions Chapter 6 Refraction of Light at Curved Surfaces Textbook Questions and Answers.

AP State Syllabus SSC 10th Class Physics Solutions 6th Lesson Refraction of Light at Curved Surfaces

10th Class Physics 6th Lesson Refraction of Light at Curved Surfaces Textbook Questions and Answers

Review of Your Previous Knowledge

Question 1.
Have you ever touched a magnifying glass with your hand?
Answer:
Yes.

Question 2.
Have you touched the glass in the spectacles used for reading with your hand?
A. Yes.

Question 3.
Is it a plane or curved surface?
Answer:
Curved surface.

Question 4.
Is it thicker in the middle or at the edge?
Answeer:
Magnifying glass and some spectacle are thicker in middle whereas some spectacles are thicker at edge.

Improve Your Learning

Question 1.
A man wants to get a picture of a zebra. He photographed a white donkey after fitting a glass, with black stripes, on to the lens of his camera. What photo will he get? Explain. (AS1)
(OR)
A person wants to get a picture of zebra and he photographed a white donkey fitting a glass with black stripes. Does he get photo of zebra? Explain.
Answer:
The person was unable to gel the picture <>l zebra because only two rays are enough to form complete image after convergence. So he will get the image of white donkey but the intensity may be less.
(OR)
He will get a picture of while donkey because e\ery part of lens forms an image so if you cover lens with stripes still it forms a complete image. However, the intensity of the image will be reduced.

Question 2.
Two converging lenses are to be placed in the path of parallel rays so that the rays remain parallel after passing through both lenses. How should the lenses be arranged? Explain with a neat ray diagram. (AS1)
Answer:

• Two lenses are placed in the path of parallel rays as shown in figure.
• The first lens is placed in the direction of parallel lines, which converges at focus.
• The second lens is arranged so that it is the focus of 2nd then emerging rays will be parallel.

Question 3.
The focal length of a converging lens is 20 cm. An object is 60 cm from the lens. Where will the image be formed and what kind of image is it? (AS1)
Answer:
f = 20 cm (by sign conversion f = + 20 cm)
u = 60 cm (by sign conversion u = – 60 cm)

Image will be formed at 30cm in between F₁, and 2F1. Image is real, inverted and diminished.

Question 4.
A double convex lens has two surfaces of equal radii ‘R’ and refractive index n = 1.5. Find the focal length ‘f’. (AS1)
(OR)
What is the focal length ‘f, when its double convex lens has two surfaces of equal radii ‘R’ and refractive index n = 1.5?
Answer:
R₁ = R₂ = R (suppose)
Focal length (f) = ?; Refractive index (n) = 1.5

∴ Focal length of lens = Radius of curvature of surface.

Question 5.
Write the lens maker’s formula and explain the terms in it. (AS1)
(OR)
Ravi wants to make a lens. Which formula he has to follow ? Write the formula and explain the terms in it.
(OR)
Write lens formula.
Answer:
Lens maker’s formula:
\(\frac{1}{\mathrm{f}}=(\mathrm{n}-1)\left(\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right)\)
n = Refractive index of the medium
R₁ = Radius of curvature of 1 st surface
R₂ = Radius of curvature of 2nd surface
f = Focal length

Question 6.
How do you verify experimentally that the focal length of a convex lens is increased when it is kept in water? (AS1)
(OR)
Write an activity to show that the focal length of a lens depends on its surrounding medium.
Answer:
Aim :
To prove focal length of convex lens is increased when it is kept in water.

Apparatus :
Convex lens, water, cylindrical vessel, circular lens holder, stone.

Procedure :

1. Take a cylindrical vessel like glass tumbler.
2. Its height must be greater than the focal length of lens, (the around four times focal length of lens).
3. Keep a black stone inside the vessel at its bottom.
4. Pour the water into the vessel such that the height of the water level from the top of the stone is greater than the focal length of lens.
5. Now dip the lens horizontally using a circular lens holder.
6. Set the distance between stone and lens that is equal to or less than focal length of lens.
7. Now see the stone through the lens.
8. We can see the image of the stone.
9. If we dip the lens to a certain height which is greater than the focal length of lens in air, still we can see the image.
10. This shows that the focal length of convex lens has increased in water.
11. Thus we conclude that the focal length of lens depends upon the surrounding medium.

Note : For convenience, use 5 or 10 cm focal length convex lens.

Question 7.
How do you find the focal length of a lens experimentally? (AS1)
Answer:

• Take the lens (Ex : Convex), which focused towards the distant object.
• A white coated screen (Ex : White paper) is placed on the other side of the lens.
• Adjust the screen till you get a clear image of the object.
• At this position measure the distance between the lens and screen which is equal to the focal length of the lens.

Question 8.
Harsha tells Siddhu that the double convex lens always behaves like a convergent lens. But Siddhu knows that Harsha’s assertion is wrong and corrected Harsha by asking some questions. What are the questions asked by Siddhu? (As2)
Answer:
The questions asked by Siddhu :

1. Is the object placed beyond 2f point?
2. Is the object located at 2f point?
3. Is the object located in between the 2f and the focal point?
4. Is the object located at the focal point?
5. Is the object located in front of the focal point?
6. Is the lens kept in a medium with refractive index less than lens or more than lens?

Question 9.
Assertion (A): A person standing on the land appears taller than his actual height to a fish inside a pond. (AS2)
Reason (R) : Light bends away from the normal as it enters air from water.
Which of the following is correct? Explain.
a) Both A and R are true and R is the correct explanation of A.
b) Both A and R are true and R is not the correct explanation of A.
c) A is true but R is false.
d) Both A and R are false.
e) A is false but R is true.
Answer:
Answer a is correct.
Explanation :
Because the light travelling from water to air it bends away from the normal so the fish observes the apparent image of the person, appears taller than his original.

Question 10.
A convex lens is made up of three different materials as shown in the figure Q-10. How many of images does it form? (AS2)

Answer:

• A lens made of three different materials of refractive indices say n₁, n₂ and n₃.
• These three materials will have three different refractive indices. Thus for a given object it forms three images.

Question 11.
Can a virtual image be photographed by a camera? (AS2)
Answer:
Yes, we can.
Ex : – A plane mirror forms a virtual image, we can able to take photograph of that image in plane mirror.

Question 12.
You have a lens. Suggest an experiment to find out the focal length of the lens. (AS3)
(OR)
Through an experiment, find out the focal length of the lens.
Answer:
Aim :
To find focal length of given lens.

Apparatus :
Object (candle), convex lens, v – stand, screen.

Procedure :

• Take a v-stand and place it on a long table at the middle.
  Place a convex lens on the v-stand. Imagine the principal axis of the lens.
• Light a candle and ask your friend to take the candle far away from the lens along the principal axis.
• Adjust a screen (a sheet of white paper placed perpendicular to the axis) which is on other side of the lens until you get an image on it.
• Measure the distance of the image from the v-stand of lens (image distance V) and also measure the distance between the candle and stand of lens (object distance ‘u’). Record the values in the table.

• Now place the candle at a distance of 60 cm from the lens, try to get an image of the candle flame on the other side on a screen. Adjust the screen till you get a clear image.
• Measure the image distance V and object distance ‘u’ and record the values in table.
• Repeat the experiment lor various object distances like 50 cm, 40 cm, 30 cm, etc. Measure the image distances in all cases and note them in table.
• Using the formula \(\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\), find f in all the cases. We will observe the value ‘f is equal in all cases. This value off is the focal length of the given lens.

Question 13.
Let us assume a system that consists of two lenses with focal length f₁, and f₂ respectively. How do you find the focal length of the system experimentally, when
i) two lenses are touching each other
ii) they are separated by a distance ‘d’ with common principal axis? (AS3)
Answer:
Experimental Proof:
i) Two lenses are touching each other :
Aim :
To find focal length of combination of two convex lenses, touching each other. Material required : Convex lenses – 2 (with known focal lengths say f, and f2); V-stands – 2, candle, screen scale.

Procedure:

• Place two V-stands with two convex lenses as they touch each other on a table.
• Place a candle (object) far away from the lenses.
• Adjust a screen, which is placed other side of the lenses until we get a clear image on it.
• At that position, measure the image distance (v) and object distance (u).
• Do this experiment for several object distances and record in the given table.

ii) They are separated by a distance of ‘d’ :
Procedure :

• Now place v-stands along with lenses with distance’d’.
• Do the same procedure again.
• Record the observations in the given table.
• Find the average of the ‘f’_comb.

Question 14.
Collect the information about the lenses available in an optical shop. Find out how the focal length of a lens may be determined by the given power’ of the lens. (AS4)
Answer:
I had collected the information regarding different lenses available at optical shops.
The relationship between power and focal length is power (D) = \(\frac{1}{f}\). f is in meters.

Question 15.
Collect the information about lenses used by Galileo in his telescope. (AS4)
(OR)
What lenses are used by Galileo in his telescope?
Answer:

A Galilean telescope is defined as having one convex lens and one concave lens. The concave lens serves as the ocular lens or the eye piece, while the convex lens serves as the objective. The lens are situated on either side of a tube such that the focal point of the ocular lens is the same as the focal point for the objective lens.

Question 16.
Use the data obtained by activity – 2 in table-1 of this lesson and draw the graphs of u vs v and \(\frac{1}{u}\) vs \(\frac{1}{v}\) (AS5)
(OR)
By obtaining data from activity – 2 in table – 1 of this lesson, draw the graphs of u vs v and \(\frac{1}{u}\) vs \(\frac{1}{v}\)
Answer:
Graph of u – v using data obtained by activity – 2. Take lens with focal length 30 cm.

The graph looks like this

The shape of the graph is rectangular hyperbola.

Graph of \(\frac{1}{u}\) – \(\frac{1}{v}\)

For these values the graph is straight line which touches the axis as shown in figure.

Question 17.
Figure shows ray AB that has passed through a divergent lens. Construct the path of the ray up to the lens if the F position of its foci is known. (AS5)

Answer:

The path of the ray up to the lens if the position of foci is known for ray AB is diverging lens or concave lens path.

Question 18.
Figure shows a point light source and its image produced by a lens with an optical axis N₁, N₂. Find the position of the lens and its foci using a ray diagram. (AS5)

Answer:

1. The object is in between focus and optic centre.
2. The image is virtual, erect and magnified. Nv
3. l is the lens, ‘O’ is the object and T is the image.

Question 19.
Find the focus by drawing a ray diagram using the position of source S and the image S’ given in the figure. (AS5)

Answer:

1.  Image is real.
2. l’ is lens, ‘O’ is object and T is image.
3.  Lens is convex.

(Or)

1. Image is real.
2. l’ is lens, ‘O’ is object and ‘I’ is image.
3. Lens is convex.

Question 20.
A parallel beam of rays is incident on a convergent lens with a focal length of 40 cm. Where should a divergent lens with a focal length of 15 cm be placed for the beam of rays to remain parallel after passing through the two lenses? Draw a ray diagram. (AS5)
Answer:

1. A parallel beam of rays when incident on a convergent lens, after refraction they meet at the focus of the lens.

2. A beam of rays which is incident on a divergent lens, after refraction, pass parallel to the principal axis. If we extend these incident rays, they seems to meet at focus of the lens.

3. Hence the divergent lens should be kept at 25 cm distance from convergent lens (40 – 15 = 25 cm) as shown in the figure.

PF = 40 cm (Focal length of convergent lens)
P’F = 15 cm (Focal length of divergent lens)
PP’ = 40 – 15 = 25 cm (Position of divergent lens)

Question 21.
Draw ray diagrams for the following positions and explain the nature and position of image.
i) Object is placed at 2F₂
ii) Object is placed between F₂ and optic centre P. (AS5)
Answer:
i) Object is placed at 2F₂:

Nature : Real, inverted and diminished.
Position : Image is formed on the principal axis between the points F₁, and 2F₁.

ii) Object is placed between F₂ and optic centre P :

Nature : Virtual, erect and magnified.
Position : Same side of the lens where object is placed.

Question 22.
How do you appreciate the coincidence of the experimental facts with the results obtained by a ray diagram in terms of behaviour of images formed by lenses? (AS6)
Answer:

• Ray diagrams are very useful in optics.
• By the ray diagrams, we can easily find the values of image distance, object distance, focal length, radius of curvature, magnification, etc.
• These results are exactly equal to the result gotten by an experiment.
• For example : In the experiment, with a convex lens, we get clear image of an object, on a screen by adjusting the screen.

Then, we measure the image distane (v) practically. This takes more time and requires equipped lab also.

But, by simply draw a ray diagram on a paper, we can get exact image distance (v) very easily, without lab.

• So, ray diagrams are very useful in the construction of microscopes, telescopes, etc.
• Hence, one can trust and depend on the result of ray diagrams instead of several lab experiments.
• So, I appreciate the ray diagrams.

Question 23.
Find the refractive index of the glass which is a symmetrical convergent lens if its focal length is equal to the radius of curvature of its surface. (AS7)
Answer:
Given that lens is convergent symmetrical

Question 24.
Find the radii of curvature of a convexo – concave convergent lens made of glass with refractive index n = 1.5 having focal length of 24 cm. One of the radii of curvature is double the other. (AS7)
Answer:

Question 25.
The distance between two point sources of light is 24 cm. Where should a convergent lens with a focal length of f = 9 cm be placed between them to obtain the images of both sources at the same point? (AS7)
Answer:
For Source S₁ :

∴ The convex lens may be placed between the two sources, such that a distance of 18 cm from one source, and 6 cm from other source.

Question 26.
Suppose you are inside the water in a swimming pool near an edge. A friend is standing on the edge. Do you find your friend taller or shorter than his usual height? Why? (AS7)
(OR)
If your friend is standing near an edge of the swimming pool and you are in the water, do you find he is taller or shorter than his usual height?
Answer:

1. My friend appears to be taller because the light is travelling from rarer to denser.
2. The rays bend in such away that they seems to be coming from long distance.
3. So it is actually apparent image of my friend which appears to be taller due to refraction.

Fill in the Blanks

1. The rays from the distant object, falling on the convex lens pass through ……………….. .
2. The ray passing through the ……………….. of the lens is not deviated.
3. Lens formula is given by ……………….. .
4. The focal length of the plano-convex lens is 2R where R is the radius of curvature of the surface. Then the refractive index of the material of the lens is ……………….. .
5. The lens which can form real and virtual images is ……………….. .
Answer:

1. Tocus
2. optical centre
3. \(\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\)
4. 1.5
5. convex lens

Multiple Choice Questions

1. Which one of the following materials cannot be used to make a lens?
A) water
B) glass
C) plastic
D) clay
Answer:
D) clay

2. Which of the following is true?
A) The distance of virtual image is always greater than the object distance for convex lens.
B) The distance of virtual image is not greater than the object distance for convex lens.
C) Convex lens always forms a real image.
D) Convex lens always forms a virtual image.
Answer:
B) The distance of virtual image is not greater than the object distance for convex lens.

3. Focal length of the plano-convex lens is when its radius of curvature of the surface is R and n is the refractive index of the lens.

4. The value of the focal length of the lens is equal to the value of the image distance when the rays are
A) passing through the optic centre
B) parallel to the principal axis
C) passing through the focus
D) in all the cases
Answer:
D) in all the cases

5. Which of the following is the lens maker’s formula?

Answer:
C

10th Class Physics 6th Lesson Refraction of Light at Curved Surfaces Additional Questions and Answers

Question 1.
Derive a relation between refractive indices of two media (n₁, n₂), object distance (u), image distance (v) and radius of curvature (R) for a curved surface.
(OR)
Derive \(\frac{\mathbf{n}_{2}}{\mathbf{v}}-\frac{\mathbf{n}_{1}}{\mathbf{u}}=\frac{\mathbf{n}_{2}-\mathbf{n}_{1}}{\mathbf{R}}\)
(OR)
Derive curved surface formula.
Answer:

• Consider a curved surface separating two media of refractive indices n₁, and n₂.
• A point object is placed on the principal axis at point ‘O’.
• The ray which travels along the principal axis passes through the pole undeviated.
• The second ray, which forms an angle with a princi¬pal axis, meets the interface at A. The angle of incidence is Q₁. The ray bends and passes through the second medium along the line AI. The angle of refraction is Q₂.
• The two refracted rays meet at I and the image is formed there.
• 6) Let the angle made by the second refracted ray with principal axis be γ and the angle between the normal and principal axis be β.
• From figure,

PO = u (object distance), PI = v (Image distance),
PC = R (radius of curvature) and n₁, n₂ are refractive indices of the media.
From ∆ACO, θ₁ = α + β
∆ACI, β = θ₂ + γ
⇒ θ₂ = β – γ
According to Snell’s law, n₁sin θ₁ = n₂ sin θ₂.
∴ n₁ sin (α + β) = n₂ sin (β – γ) …………….. (1)
As per paraxial approximation,
sin (α + β) = α + β and sin (β – γ) = β – γ.
∴ (1) ⇒ n₁(α + β) = n₂ (β – γ)
⇒ n₁ α + n₁β = n₂ β – n₂ γ — (2)
Since all angles are small, we can write

∴ This is the required relation for curved surfaces.

Question 2.
Derive expression for lens maker’s formula.
(OR)
Prove \(\frac{1}{\mathbf{f}}=(\mathbf{n}-\mathbf{1})\left(\frac{1}{\mathbf{R}_{1}}-\frac{1}{\mathbf{R}_{2}}\right)\).
Answer:

Procedure :

• Imagine a point object ‘O’ placed on the principal axis of the thin lens
• Let this lens be placed in a medium of refractive index n_a and let refractive index of lens be n_b.
• Consider a ray, from ‘O’ which is incident on the convex surface of the lens with radius of curvature R₁ at A.
• The incident ray refracts at A.
• It forms image at Q, if there were no concave surface.
• From figure Object distance PO = – u;

Image distance PQ = v = x
Radius of curvature R = R₁
n₁ = n_a and n₂ = n_b.

• But the ray that has refracted at A suffers another refraction at B on the concave surface with radius of curvature (R₂).
• At B the ray is refracted and reaches I.
• The image Q of the object due to the convex surface. So I is the image of Q for concave surface.
• Object distance u = PQ = + x
  Image distance PI = v
  Radius of curvature R = – R₂
• The refraction of the concave surface of lens is medium -1 and surrounding is medium – 2.
  ∴ n₁ = n_b and n₂ = n_a

Question 3.
Derive the lens formula.
Answer:
1. Consider an object 00′ placed on the principal axis in front of a convex lens as shown in the figure. Let II’ be the real image formed by the lens, i.e. the other side of it.

2. From the figure : PO, PI, PFt are the object distance, image distance and focal length respectively.

10th Class Physics 6th Lesson Refraction of Light at Curved Surfaces InText Questions and Answers

10th Class Physics Textbook Page No. 64

Question 1.
What happens to a ray that is incident on a curved interface separating the two media? Are the laws of refraction still valid?
Answer:
It undergoes deviation from its path. Yes, the laws of reflection are still valid.

Question 2.
How do rays betid when they are incident on a curved surface?
Answer:
A ray will bend towards the normal when it travels from rarer to denser medium and bends away from the normal when it travels from denser to a rarer medium.

10th Class Physics Textbook Page No. 65

Question 3.
What happens to ray that travels along the principal axis? Similarly, a ray that travels through the centre of curvature?

Answer:
According to Snell’s law the ray which travels along the normal drawn to the surface does not deviate from its path. Hence both rays in the given condition travel along normal, so they do not deviate.

Question 4.
What difference do you notice in the refracted rays in 4 (a) and 4 (b)? What could be the reason for that difference?

Answer:

• In figure 4 (a) ray travelling parallel to the principal axis strikes a convex surface and passes from a rarer medium to a denser medium.
• In figure 4 (b) a ray travelling parallel to the principal axis strikes a convex surface passes from a denser medium to a rarer medium.
• Figure 4 (a) : The refracted ray moves towards the normal.
• Figure 4 (b) : The refracted ray moves away from the normal.
  Reason : The main reason is that light passes through different media.

10th Class Physics Textbook Page No. 66

Question 5.
What difference do you notice in refracted rays in 4 (c) and 4 (d)? What could be the reasons for that difference?
(OR)
Draw the ray diagrams when the incident ray passes through the curved surfaces.
a) Rarer medium to denser medium.
b) Denser medium to rarer medium.

Answer:

• In figure 4 (c) a ray travelling parallel to the principal axis strikes a concave surface and passes from a denser medium to a rarer medium.
• In figure 4 (d) a ray travelling parallel to the principal axis strikes a concave surface and passes from a rarer medium to a denser medium.

Reasons :

• Figure 4 (c) :The refracted ray reaches a particular point on the principal axis.
• Figure 4 (d) : The refracted ray moves away from the principal axis.
• The main reason is that light passes through different media.

Question 6.
You might have observed that a lemon in the water of a glass tumbler appears bigger than its actual size, when viewed from the sides of tumbler.
1) How can you explain this (appeared) change in size of lemon?
Answer:
It can be explained by using refraction. When light travels from one medium to another medium it undergoes refraction.

2) Is the lemon that appears bigger in size an image of lemon or is it the real lemon?
Answer:
That is image of lemon.

3) Can you draw a ray diagram to explain this phenomenon?
Answer:

10th Class Physics Textbook Page No. 70

Question 7.
What happens to the light ray when a transparent material with two curved surfaces is placed in its path?
Answer:
The light ray undergoes refraction.

Question 8.
Have you heard about lenses?
Answer:
Yes, we have heard about lenses. A transparent material bounded by two spherical v surfaces is called lens.

Question 9.
How does a light ray behave when it is passed through a lens?
Answer:
A light ray will deviate from its path in some cases and does not deviate in some other cases.

10th Class Physics Textbook Page No. 72

Question 10.
How does the lens form an image?
Answer:
Lens forms an image through converging light rays or diverging light rays.

Question 11.
If we allow a light ray to pass through the focus, which path does it take?
Answer:
The ray passing through the focus takes a parallel path to principal axis after refraction.

10th Class Physics Textbook Page No. 73

Question 12.
What happens when parallel rays of light fall on a lens making some angle with the principal axis?
Answer:’
The rays converge at a point (or) appear to diverge from a point lying on the focal plane.

Question 13.
What do you mean by an object at infinity? What type of rays fall on the lens?
Answer:
The distance between the lens and the object is very much greater than when compared to object size is known as object at infinity. Parallel rays fall on the lens.
The object at infinity means distant object. The rays falling on the lens from an object at infinity are parallel to principal axis.

10th Class Physics Textbook Page No. 77

Question 14.
Could you get an image on the screen for every object distance with a convex lens?
Answer:
No, when the object is placed between pole and focus we will get virtual, erect and enlarged image on the other side of the- object.

Question 15.
Why don’t you get an image for certain object distances?
Answer:
Because at those distances the light rays diverge each other.

Question 16.
Can you find the minimum limiting object distance for obtaining a real image? What do you call this minimum limiting object distance?
Answer:
Yes, this minimum limiting object distance is called focal length.

Question 17.
When you do not get an image on the screen, try to see the image with your eye directly from the place of the screen. Could you see the image? What type of image do you see?
Answer:
Yes, we can see the image. This is a virtual image which we cannot capture on screen.

Question 18.
Can you find the image distance of a virtual image? How could you do it?
Answer:
We can find the image distance of virtual image by using lens formula \(\frac{1}{\mathrm{f}}=\frac{1}{\mathrm{v}}-\frac{1}{\mathrm{u}}\) (if we know the focal length of lens and object distance.)

10th Class Physics 6th Lesson Refraction of Light at Curved Surfaces Activities

Activity – 1

Question 1.
Write an activity to observe the light refraction at curved surface.
Answer:
Procedure and observation :

• Draw an arrow of length 4 cm usfng a black sketch pen on a thick sheet of paper.
• Take an empty cylindrical-shaped transparent vessel.
• Keep it on the table.
• Ask your friend to bring the sheet of paper on which arrow was drawn behind the vessel while you look at it from the other side.
• We will see a diminished image of the arrow.
• Ask your friend to fill vessel with water.
• Look at the arrow from the same position as before.
• We can observe an inverted image.

Explanation :

• In the first case, when the vessel is empty, light from the arrow refracts at the curved interface, moves through the glass, enters in to air then it again undergoes refraction on the opposite curved surface of vessel and comes out into the air.
• In this way light travels through two media, comes out of the vessel and forms a diminished image.
• In the second case, light enters the curved surface, moves through water, comes out of the glass and forms an inverted image.

Lab Activity

Question 2.
Write an activity to know the characteristics of image due to convex lens at various distances.
Answer:
Aim:
Determination of focal length of bi-convex lens using UV method.

Material Required :
V Stand, convex lens, light source, screen, meter scale. Take a V-stand and place it on a long (nearly 2m) table at the middle. Place a convex lens on the v-stand. Imagine the principal axis of the lens. Light a candle and ask your friend to take the candle far away from the lens along the principal axis. Adjust a screen (a sheet of white paper placed perpendicular to the axis) which is on other side of the lens until you get an image on it.

Procedure :

1. Take a V-stand and place a convex lens on this stand.
2. Imagine the principal axis of the lens.
3. Light a candle and ask your friend to take the candle far away from the lens along the principal axis.
4. We use a screen because it forms a real image generally which will form on a screen. Real images cannot be seen with an eye.
5. Adjust the screen, on other side of lens until clear image forms on it.
6. Measure the distance of the image from the stand and also measure the distance between the candle and stand of lens.
7. Now place the candle at a distance of 60 cm from the lens such as the flame of the candle lies on the principal axis of the lens.
8. Try to get an image of candle flame on the other side on a screen.
9. Adjust the screen till you get a clear image.
10. Measure the distance of image (v) from lens and record the value of’u’ and V in the table.
11. Repeat this for various distances of images; in all cases note them in the table.

Observation :

Conclusion : From this we conclude that a convex lens forms both real and virtual images when object is placed at various positions.

AP State Board Syllabus AP SSC 10th Class Biology Solutions Chapter 2 Respiration – The Energy Releasing System Textbook Questions and Answers.

AP State Syllabus SSC 10th Class Biology Solutions 2nd Lesson Respiration – The Energy Releasing System

10th Class Biology 2nd Lesson Respiration – The Energy Releasing System Textbook Questions and Answers

Improve your learning

Question 1.
Distinguish between
(a) Inspiration and Expiration
(b) Aerobic and Anaerobic respiration
(c) Respiration and Combustion
(d) Photosynthesis and Respiration
Answer:
(a) Inspiration and Expiration:

(b) Aerobic respiration and Anaerobic respiration:
(OR)
Respiration is energy-producing process in the organisms. It takes place both in the presence and absence of oxygen. Laxmi said there are some differences between the two processes. How do you support her?
Answer:

Aerobic respiration	Anaerobic respiration
1. It takes place in the presence of oxygen.	1. It takes place in the absence of oxygen.
2. In aerobic respiration, complete oxidation of glucose takes place.	2. In anaerobic respiration, the glucose molecule is incompletely oxidised.
3. End products are CO2 and water.	3. End products are either ethyl alcohol or lactic acid and CO2.
4. Lot of energy is liberated (38 ATP).	4. Relatively small energy is liberated (2 ATP).
5. It occurs in plant’s and animal’s cells.	5. Occurs in many anaerobic bacteria and human muscle cells.
6.	6.
7. It has two stages – Glycolysis and Krebs cycle.	7. It has two stages – Glycolysis and Fermentation.

(c) Respiration and Combustion:
(OR)
Even though both are oxidation processes, combustion and respiration are different in many aspects. Explain those differences.
(OR)
Combustion and respiration are oxidative processes but still there are differences between them. What are they?
(OR)
Write the differences between respiration and combustion.
Answer:

(d) Photosynthesis and Respiration:

Photosynthesis	Respiration
1. Occurs only in all plants and photo­synthetic bacteria.	1. Occurs in all living organisms.
2. Takes place in the presence of sunlight.	2. Takes place throughout day and night.
3. A plant can survive without performing photosynthesis for few days.	3. No organism can survive without respiration for few minutes even.
4. In plants, only few cells perform photosynthesis.	4. All living cells in an organism perform this process.
5. Raw materials are C02 and water.	5. Uses carbohydrates and oxygen.
6. Oxygen is liberated.	6. Carbon dioxide is released.
7. It occurs in chloroplast.	7. It takes place in cytoplasm and mitochondria.
8. Adds weight to the organism.	8. Decrease weight of the organism.
9. It is an anabolic process.	9. It is a catabolic process.
10.	10.

Question 2.
State two similarities between aerobic and anaerobic respiration.
Answer:
Similarities between aerobic and anaerobic respiration:

1. Both are catabolic processes.
2. Both aerobic and anaerobic respiration takes place in all cells.
3. Energy is released in both the processes.
4. CO₂ is the end product of both processes.
5. First stage of both respiration is glycolysis.
6. Respiratory substances in both processes are glucose, fatty acids and amino acids.

Question 3.
Food sometimes enters the wind pipe and causes choking. How does it happen?
Answer:

1. Pharynx is the common passage of both air and food.
2. From here air enters into trachea and food enters into oesophagus.
3. Pharynx is connected to larynx through glottis a slit like opening.
4. A cartilagenous flap called EPIGLOTTIS act as a lid over glottis and prevents food from entering into trachea during swallowing.
5. Any food particles enters the trachea it causes chocking.
6. Sometimes the food particles are forced back by cough.

Question 4.
Why does the rate of breathing increase while walking uphill at a normal pace in the mountains? Give two reasons.
Answer:
The rate of breathing increases while walking uphill at a normal pace in the mountains.

1. It is because as we go up the hill above sea level the concentration of oxygen is greatly reduced. So we have to breathe more to get required amount of oxygen.
2. While walking uphill a lot of oxygen is used by our body to release energy from glucose.
3. This leads to lack of oxygen in the cells.
4. We take in oxygen when we breathe.
5. Hence to increase the amount of oxygen intake there is an increase in breathing rate during walking uphill.

Question 5.
Air leaves the tiny sacs in the lungs to pass into capillaries. What modification is needed in the statement?
Answer:

1. Gaseous exchange takes place within the lungs by diffusion from the alveoli to blood capillaries and vice versa.
2. The carbondioxide in the blood is exchanged for oxygen in alveoli.
3. This sentence may be modified as “Air that contains oxygen reaches the tiny sacs in the lungs to pass into capillaries.

Question 6.
Plants photosynthesize during daytime and respire during the night. Do you agree to this statement? Why? Why not?
Answer:

1. No, I do not agree with this statement. Plants photosynthesize during daytime only and respire during the daytime as well as night time also.
2. During daytime when photosynthesis occurs in the presence of sunlight. Oxygen is produced. The leaves use some of this oxygen for respiration and the rest diffuses into air.
3. During daytime CO₂ produced by respiration is all used up in photosynthesis by leaves.
4. At night time no photosynthesis occurs and oxygen diffuses into leaves to carryout respiration.

Question 7.
Why does a deep sea diver carry oxygen cylinder on his/her back?
Answer:

1. When we go deep into the sea, the oxygen level decreases. Oxygen is in dissolved state in water.
2. Humans are adapted for utilizing oxygen in gaseous state. They cannot use dissolved oxygen for breathing.
3. Only aquatic animals like fish can utilize the dissolved oxygen for breathing using gills.
4. Human beings have lungs for respiration. Therefore, sea divers have to carry oxygen cylinders in their back so as to receive oxygen.
5. If they do not carry them, they do not get oxygen and there is a chance even to die.

Question 8.
How are alveoli designed to maximise the exchange of gases?
Answer:
The human lungs have been designed to maximise the exchange of gases as follows.

1. The interior of lung is divided into millions of small chambers called alveoli.
2. The presence of millions of alveoli in the lungs provide a very large surface area.
3. If all alveoli of our lungs are spread out they will cover an area of nearly 160 m².
4. Availability of large surface area maximises the exchange of gases.

Question 9.
Where will the release of energy from the glucose in respiration take place? Mala writes lungs, while Jiya writes muscles. Who is correct and why?
Answer:

1. Respiration is the process of releasing energy from the breakdown of glucose.
2. Respiration takes place in every living cell, all the time.
3. All cells need to respire in order to produce the energy that they require.
4. During respiration the release of energy from the glucose takes place in muscles but not in lungs.
5. So Jiya is correct. The energy is released from the muscle cells during respiration. Only gaseous exchange takes place in lungs.

Question 10.
What is the role of epiglottis and diaphragm in respiration?
Answer:
Epiglottis:

1. Epiglottis, a flap like muscular valve controls movement of air and food towards their respective passages.
2. Epiglottis is partly closed when we swallow food and it opens more widely when we take a breath and air enters the lungs.
3. Epiglottis allows air pass through the larynx and the respiratory system.
   

Diaphragm :

1. The diaphragm in the respiratory system is the dome shaped sheet of muscle that separates the chest from the abdomen.
2. When the diaphragm contracts during inhalation it flattens out a bit. This results in the enlargement of the volume of the chest cavity.
3. This reduces the pressure in the lungs and air enters into lungs from outside the body.
4. During exhalation, the diaphragm relaxes and assumes its dome shape. This change increases the pressure on the lungs and squeezes the air through the nose to the atmosphere.
   

Question 11.
How does gaseous exchange take place at blood level?
Answer:

1. Lungs are made up of several thousands of small chambers called alveoli.
2. Within the alveoli, exchange of gases take place between the gases inside the alveoli and blood.
3. Blood arriving in the alveoli has higher CO₂ concentration which is produced during respiration by the body cells.
4. At the same time air in the alveoli has a much lower concentration of CO₂ and this allows the diffusion of CO₂ out of the blood and to alveolar air.
5. Similarly blood arriving in the alveoli has a lower oxygen concentration while air in the alveoli has a higher oxygen concentration.
6. Therefore oxygen moves into the blood by diffusion.
   

Question 12.
Explain the mechanism of gaseous exchange at bronchiole level.
Answer:

1. the trachea (wind pipe) is divided into two tubes called BRONCHI. As there are two lungs each bronchus (singular) enters the lungs on the same side.
2. In the lung, the bronchus divides into smaller and smaller branches called BRONCHIOLES which enters into each alveoli.
3. When oxygen from outside reaches the alveoli through bronchioles and the carbondioxide from alveoli moves out.
4. The inhaled air from outside enters into bronchioles through nostrils → nasal cavities → pharynx → larynx → trachea → bronchus.
5. The exhaled air from alveoli enters bronchioles → pharynx → nasal cavities → nostrils → outside.
   

Question 13.
After a vigorous exercise or work we feel pain in muscles. What is the relationship between pain and respiration?
Answer:

1. We obtain energy by oxidation of glucose molecule.
2. In the absence of oxygen (anaerobic respiration) glucose is converted to latic acid.
3. During vigorous exercise oxygen gets used up faster in the muscle cells that can be supplied by blood.
4. When oxygen supply is inadequate the muscles use energy released during the anaerobic breakdown of glucose.
5. The anaerobic respiration by muscles bring about partial breakdown of glucose to form lactic acid.
6. The accumulation of lactic acid in the muscles causes muscular pains or cramps.

Question 14.
Raju said, “Stems also respire along with leaves in plants”. Can you support this statement? Give your reasons.
Answer:
Yes. I support the statement of Raju that stems also respire along with leaves in plants.
The reasons are

1. The stems of herbaceous plants have stomata.
2. So the exchange of respiratory gases in the stems of herbaceous plants takes place through stomata.
3. The oxygen from air diffuses into the stem through stomata and reaches all the cells for respiration.
4. The carbon dioxide released during respiration diffuses out into the air through the stomata.
5. In woody stems the bark has lenticels for gaseous exchange. Through lenticels, oxygen diffuses in and carbon dioxide diffuses out into the air.
   

Question 15.
What happens if diaphragm is not there in the body?
Answer:

1. The lungs cannot draw in air or push it out by themselves. The chest wall muscles and the diaphragm helps the lungs in moving air into and out of them.
2. If diaphragm is not there in the body, we would not be able to breathe.
3. The diaphragm is the major muscle in the process of respiration.
4. It separates the thoracic and abdominal cavities.
5. In the absence of diaphragm, the relaxation and contraction of the chest wall muscles do not take place and thereby inspiration and expiration become difficult that leads to death of the person.

Question 16.
If you have a chance to meet pulmonologist, what questions are you going to ask about pulmonary respiration?
Answer:
If I have a chance to meet pulmonologist, I would like to ask the following questions:

1. What is pulmonary respiration?
2. What is the organ involved in pulmonary respiration?
3. What is the name of blood vessel that brings deoxygenated blood to lungs?
4. What is the name of the blood vessel that carries oxygenated blood from the lungs to the heart?
5. Out of the two lungs which one is larger than the other?
6. What type of diagnostic test will be performed to assess the function of lungs?
7. What is pulmonary edema? How does it occur?
8. Can all the diseases of the lungs be cured permanently?

Question 17.
What procedure do you follow to understand anaerobic respiration in your school laboratory?
(OR) (Lab Activity)
Write the procedure and observations of the experiment which you have conducted in your laboratory to prove that CO₂ and heat are evolved during anaerobic respiration by using yeast.
(OR)
How do you prove that carbon dioxide is released during anaerobic respiration?
(OR)
How do yeast cells convert glucose solution to CO₂ and ethyl alcohol?
Answer:
Aim : To prove that CO₂ is released during anaerobic respiration.
Apparatus: Thermos flask, splitted corks, thermometer, wash bottle, glass tubes, liquid
paraffin, glucose solution, yeast cells, bicarbonate solution.
Procedure:

1. Remove dissolved oxygen from glucose solution by boiling it for a minute and then cooling it without shaking.
2. Now add some yeast to the glucose solution and fix a two-holed rubber stopper to the flask.
3. The supply of oxygen from the air can be cut off by pouring a 1cm layer of liquid paraffin into the mixture through the holes.
   
4. Insert one end of the thermometer into the thermos flask. See the mercury bulb of thermometer keep inside the solution.
5. Arrange for any gas produced by the yeast to escape through a wash bottle containing bicarbonate solution or lime water as shown in the figure.
6. Add a few drops of diazine green (Janus Green B) solution to the yeast suspension before you pour liquid paraffin over it.
7. The blue diazine green solution turns pink when oxygen is in short supply around it.
8. Warm the apparatus to about 37° F in order to speed up the test.
9. Keep the apparatus undisturbed for one or two days.

Observations :

1. After two days it can be observed that lime-water of the wash bottle turns into milky white precipitate.
2. Increase in temperature in thermometer.
3. Alcohol smell given off from the flask.

Result: These observations indicate that yeast cells respire anaerobically converting glucose solution into CO₂, ethyl alcohol and release heat energy.

Question 18.
What are your observations in the combustion of sugar activity?
Answer:
Observations in the combustion of sugar:

1. When sugar is heated, first it melts, chars and later burns producing flames.
2. When sugar is combusted, carbon dioxide and water are produced.
3. Energy is also released in the form of heat and it released at once.
4. We cannot control the combustion of sugar.
5. Intermediate products are not formed.
6. We can combust sugar in the absence of water and enzymes.
7. When combustion of sugar, heat energy is released into the atmosphere and we cannot store it for further use.

Question 19.
Collect information about cutaneous respiration in frog. Prepare a note and display them in your classroom.
(OR)
How does frog respire with the help of skin?
Answer:

1. Respiration through skin is called cutaneous respiration.
2. In frog, skin is an additional or secondary or accessory respiratory organ.
   
3. Skin is a very important respiratory organ in both on land and water.
4. One-third of the total oxygen taken up by frog is through the skin.
5. Frog also keeps its skin moist. Frog skin has a large number of mucous glands which secrete mucous onto the surface of the skin.
6. The mucous layer retains water and reduces evaporation of water from body.
7. To keep the skin wet and moist frogs jump into water very frequently.
8. Frog skin is supplied with a large number of blood vessels which help in absorbing oxygen from the water.
9. The carbon dioxide produced during to respiration, diffuses out into the water through the blood vessels present in the skin of the frog.

Question 20.
Collect information about respiratory diseases (because of pollution, tobacco) .and discuss with your classmates.
Answer:
Respiratory diseases because of pollution:

1. Irritation of eyes, nose, mouth and throat.
2. Headaches and dizziness.
3. Respiratory symptoms such as coughing and running nose.
4. Respiratory and lung diseases including
   a) Asthma attacks
   b) Chronic obstructive pulmonary disease (COPD)
   c) Reduced lung function
   d) Pulmonary cancer caused by a series of carcinogen chemicals that through inhalation
   e) Mesothelioma: A particular type of lung cancer, usually associated with expo¬sure to asbestos (it usually occurs 20 – 30 years after the initial exposure)
   f) Pneumonia: Infection of lungs caused by bacteria.
   g) Bronchitis: It is inflammation or swelling of bronchial tubes.
   h) Emphysema: It is a lung condition in which tiny air sacs in lungs alveoli fill up with water.

Respiratory diseases due to tobacco :

1. Chronic bronchitis: A long term inflammation of the bronchi is characterized by coughing.
2. Lung cancer: An abnormal continuous multiplication of cells that can result in tumors in the lining of the bronchi.
3. Emphysema: A chronic lung condition that affects the air sacs in the lungs characterized by shortness of breath, coughing, fatigue, sleep and heart problems.

Question 21.
What is the pathway taken by air in the respiratory system? Illustrate with a labelled diagram.
Answer:
The path way taken by air in the respiratory system:
Nostrils → Nasal cavity → Pharynx → Larynx → Trachea → Bronchus → Bronchioles → Alveolus → Blood.

1. Nostrils : Air enters the body through the nostrils.
2. Nasal cavity: Air is filtered and its temperature is also brought close to that of the body.
3. Pharynx: It is the junction of respiratory and digestive system. Epiglottis – a flap like muscular valve controls movement of air and food towards their respective passages.
4. Larynx: Also called voice box. This stiff box contains vocal cords. When air passes out of the lungs and over vocal cords, it causes them to vibrate. This produces sounds on the basis of our speech, song etc.
5. Trachea: This is also called wind pipe. It channels air to lungs.
6. Bronchi: Trachea at it’s lower end divides into two bronchi one leading to each lung.
7. Bronchioles: The bronchi further divided into smaller and smaller branches called bronchioles.
8. Alveoli: Clusters of air sacs called alveoli in the lungs which are very small and numerous. The gaseous exchange takes place here as blood capillaries take up oxygen and expel CO₂.
9. Blood: It carries oxygen, to each and every cell of the body and collects CO₂ from them.
   

Question 22.
Draw a block diagram showing events in respiration. Write what you understood about cellular respiration.
Answer:
Events in respiration :

Cellular respiration :

1. All living cells must carry out cellular respiration.
2. Oxidation of glucose of fatty acids releasing energy takes place in cells, hence it is called cellular respiration.
3. It can be in the presence of oxygen that is aerobic respiration or in its absence that is anaerobic respiration (fermentation).
4. Cellular respiration in prokaryotic cells like that of bacteria occurs within the cytoplasm.
5. In Eukaryotic cells cytoplasm and mitochondria are the site of cellular respiration.
6. The energy released in cellular respiration is stored in a special compound called ATP.
7. ATP is utilised for carrying out other functions in the cell.

Question 23.
How do you appreciate the mechanism of respiration in our body?
Answer:

1. Respiration is essential for life because it provides energy for carrying out all the life processes which are necessary to keep the organism alive.
2. The energy that is obtained from respiration is used to build the organism by way of cell growth, reproduction and cell repair, etc.
3. All systems in living beings need energy to survive.
4. Respiration helps to expel out the toxic carbon dioxide out of the cells. This CO₂ will be utilised by the plants to produce food materials through the process of photosynthesis.
5. The respiratory system goes into operation from the movement of our birth and works without ever stopping as long as we live our breath continues.
6. During exhalation, the vocal cords in the larynx vibrate to produce sounds and help in speaking as we like.

Question 24.
Prepare an article on anaerobic respiration to present school symposium.
Answer:
Anaerobic respiration :

1. Respiration that occurs without oxygen is known as anaerobic respiration.
2. It is present in primitive organisms and muscular cells in higher animals.
3. Alcohol, CO₂ and H₂O are end products in this process.
4. 

Merits:

1. In the absence of oxygen it is good process.
2. Mechanism is simple.
3. Suitable to microorganisms

Demerits:

1. Provides less energy
2. Not suitable to higher animals

Question 25.
Prepare a cartoon on discussion between haemoglobin and chlorophyll about respiration.
Answer:
Discussion between haemoglobin and chlorophyll about respiration:

Haemoglobin: Hello good morning chlorophyll. How are you?

Chlorophyll: Very good morning haemoglobin. I am fine.

Haemoglobin: I am also doing well. Let me know something about you.

Chlorophyll: I am a green coloured pigment present in leaves of plants.

Haemoglobin: How many types of chlorophylls are there ?

Chlorophyll: We are four types i.e., chlorophyll – a, chlorophyll – b, chlorophyll – c and chlorophyll – d.

Haemoglobin: May I know your job in leaves?

Chlorophyll: Yes. Why not? I am an essential factor required to prepare food through the process of photosynthesis in plants.

Haemoglobin: Oh! You are participating in the process of preparing food materials by green plants.

Chlorophyll: Now tell me about your presence.

Haemoglobin: I am present only in animal cells. That too in the red blood cells of the blood. The red colour of the blood is due to my presence.

Chlorophyll: Then tell me about your function in respiration?

Haemoglobin: During respiration, I carry oxygen to the cells in the body tissues.

Chlorophyll: How are you able to do this?

Haemoglobin: I have an oxygen binding element iron. It binds oxygen on four corners of it. I form oxy-haemoglobin with oxygen in the lungs.

Chlorophyll: What happens to the digested food in the cells?

Haemoglobin: In cells, oxygen breakdown the glucose molecule into C02 and H20 releasing large amount of energy. Around 38 ATP molecules are produced.

Chlorophyll: What is the use of this energy?

Haemoglobin: This energy is utilised by the cell to carry other functions.

Chlorophyll: Thank you haemoglobin. You have taught me everything about respiration. In our next meeting we will discuss another topic.

Haemoglobin: Thank you chlorophyll for your interest and patience.

Fill in the blanks.

1. Exhaled air contains ———– and ———–.
2. A flap like muscular valve controls movement of air and food is ———–.
3. Energy currency of the cell is called ———–.
4. Lenticels are the respiratory organs that exist in ———– part of the plant.
5. Mangrove trees respire with their ———–.

Answer:

1. carbon dioxide, water vapour
2. Epiglottis
3. ATP (Adenosine Tri Phosphate)
4. stem
5. aerial roots

Choose the correct answer.

6. We will find vocal cords in [ ]
A) Larynx
B) Pharynx
C) Nasal cavity
D) Trachea
Answer: A

7. Cluster of air sacs in lungs are called [ ]
A) Alveoli
B) Bronchi
Answer: A

8. Which of the following is correct ? [ ]
i) The diaphragm contracts – volume of chest cavity increased
ii) The diaphragm contracts – volume of chest cavity decreased
iii) The diaphragm expands – volume of chest cavity increased
iv) The diaphragm expands – volume of chest cavity decreased
A) i B) i and ii C) ii and iii D) iv
Answer: A

9. Respiration is a catabolic process because of [ ]
A) Breakdown of complex food molecules
B) Conversion of light energy
C) Synthesis of chemical energy
D) Energy storage
Answer: A

10. Energy is stored in [ ]
A) Nucleus
B) Mitochondria
C) Ribosomes
D) Cell wall
Answer: B

10th Class Biology 2nd Lesson Respiration – The Energy Releasing System

Activity – 1

How do you test the presence of water vapour and heat in the exhaled air?
Answer:

1. Keep your palm around an inch away from your nose.
2. Feel you breathing out.
3. Do not remove your palm until you have finished the activity.
4. Breathe steadily for 1 – 2 minutes.
5. Now take a piece of any fruit.
6. Chew and before swallowing it keep the fingers of the other palm on your neck, now swallow it.

Questions:

1. What did you notice? What happens to your breath as you try to swallow?
   Answer:
   We cannot swallow while breathing. We usually stop breathing when we swallow food.
2. What is helping you to swallow without deflecting it to the windpipe?
   Answer:
   Epiglottis is helping me to swallow without deflecting food to the windpipe.

Activity – 2
Write an experiment to observe changes during combustion of sugar.
(OR)
What are your observations in combustion of sugar activity.
Answer:
Aim: To observe changes during combustion of sugar.
Apparatus: Wooden stand, test tubes, rubber stopper, delivery tube, glucose or sucrose powder, lime water, spirit lamp.
Procedure:

1. Take a small amount of glucose in a small test tube.
2. Arrange the apparatus as shown in the figure.
3. Heat the test tube until the glucose catches fire.
   

Observations :

1. In the initial stage the glucose becomes liquid.
2. Later it turns to black colour after catching fire.
3. In this process carbon dioxide and water are produced.
4. Energy is released as heat.
5. The carbon dioxide released changes lime water to milky white.

Conclusion:

1. From this experiment, we can conclude that carbon dioxide, water and heat are produced during combustion of glucose in the laboratory.
2. The carbon dioxide changes lime water to milky white in nature.

Activity – 3

How can you prove that carbon dioxide is evolved during respiration?
(OR)
Write the experimental procedure and draw the arrangement of apparatus to show that CO₂ is evoloved in respiration.
To understand that CO₂ is evolved during respiration, what experiment you have performed in your laboratory? Explain the procedure.
(OR)
Write an experiment to prove that CO₂ is released during respiration.
Answer:
Aim: To prove that CO₂ is released during aerobic respiration.
Apparatus: Two wide mouthed plastic or glass bottles, germinating seeds, dry seeds, two small injection bottles or beakers with lime water.

1. Take two wide mouthed glass bottles.
2. Keep germinating bengal gram seeds in one bottle and dry seeds in another bottle.
3. Keep two small beakers with lime water in each glass bottles.
4. Close the glass bottles tightly.
5. Keep both the sets undisturbed for one or two days.
   

Observation:

1. After two days it can be observed that lime water of the beaker placed in the bottle containing germinating seeds turns into milky white.
2. And the lime water kept in the glass bottle containing dry seeds do not change its colour.
   Result: It indicates that germinating seeds liberated carbon dioxide which turns lime
   water into milky white.

Activity – 4

Explain the procedure you have adopted in your school to prove that heat is liberated during respiration. What result we will get, if you perform this experiment with dry seeds?
(OR)
Write the procedure you have followed to observe “heat is evolved during respiration” in your laboratory. What precautions did you take during the activity?
Answer:
Aim: To prove that heat is liberated during respiration.
Apparatus: Two Thermos flasks, two thermometers, two rubber corks, dry seeds, germinating seeds.
Procedure:

1. Take a handful of moong or bazra seeds.
2. Soak the seeds in water a day before experiment.
3. Keep these soaked seeds in a cloth pouch and tie with a string tightly.
4. Next day collect the sprouts / germinated seeds from the pouch in a thermos flask and take dry seeds in another thermos flask.
5. Remove the lid and prepare a cork through which you can bore a hole to insert thermometers into two flasks in such a way that the bulb of the thermometer should dip into the germinating and dry seeds.
6. Close the thermos flasks with tight fitting rubber corks.
7. Record the initial temperature in both the flasks and record it for every two hours for at least 24 hours.
   

Observation: Constant increase in the temperature is observed in thermometer placed in the germinating seeds.
Result: Hence it is proved that germinated seeds respire and liberate heat which is responsible for increase in the temperature.
Questions:

1. Make a graph by using your observations.
   Answer:
   
2. Is there any increase in temperature?
   Answer:
   Yes, there is increase in temperature.
3. Does the temperature increase steadily or does it abruptly increase at a time of the day?
   Answer:
   The temperature in the thermometer increases steadily.
4. Where does the heat come from?
   Answer:
   The sprouting or germinating seeds respire and liberate heat.

10th Class Biology 2nd Lesson Respiration – The Energy Releasing System InText Questions and Answers

10th Class Biology Textbook Page No. 25

Question 1.
Can it be said that Priestly’s experiment helped us to find out more about composition of air? How?
Answer:
Yes, Priestly’s experiments helped to find out the composition of air when burning of charcoal, carbon dioxide is produced which is the one of the composition of air done by Lavoisier.
Another experiment with phosphorus done by Lavoisier was cleared that a gas which is the respirable air that is helped in burning was oxygen also a component of air.
Lavoisier proved experimentally that carbon dioxide and oxygen were the components of air. Lavoisier confirmed the experiments of Priestly about the gases present in the air.

Question 2.
What gas was produced by combustion according to Lavoisier?
Answer:
The gas produced by combustion is carbon dioxide.

Question 3.
What did Lavoisier find out about air from his experiments?
Answer:
A fixed air carbon dioxide and respirable air oxygen which helped in burning were liberated during his experiments.

Question 4.
What conclusion can be drawn from Lavoisier’s experiments?
A. Oxygen and carbon dioxide are the compositions of air.

10th Class Biology Textbook Page No. 26

Question 5.
Which gas do you think is Lavoisier talking about when he says chalky acid gas?
Answer:
Carbon dioxide.

Question 6.
Which gas according to Lavoisier is respirable air?
Answer:
Oxygen.

Question 7.
What steps in the process of respiration does Lavoisier mention as an inference of his experiments?
Answer:
Lavoisier mentioned that there were two steps in the respiration.
1. Inspiration: Breathing oxygen.
2. Expiration: Eliminating carbon dioxide from lungs.

Question 8.
It is a common observation that our breath is warmer than the air around us ; does respiration have anything to do with this?
Answer:
Our exhaled air is warmer than the air around us because heat is liberated during respiration.

10th Class Biology Textbook Page No. 27

Question 9.
What does this experiment indicate?
Answer:
This experiment indicates that carbon dioxide is liberated during respiration.

Question 10.
Which gas turns lime water milky?
Answer:
Carbon dioxide.

Question 11.
Which gas do you think might be present in greater quantities in the air we breathe out as compared to air around us?
Answer:
Nitrogen (78%) is present in greater quantities in the air.

Question 12.
We are also aware of the fact that water vapour deposits on a mirror if we breathe out on it; where does this water vapour come from in Exhaled air?
Answer:
Water vapour is liberated during respiration.

10th Class Biology Textbook Page No. 29

Question 13.
Why are we advised not to talk while eating food?
Answer:

1. When we are eating food, epiglottis helps to avoid food entering into trachea.
2. If we talk while we eat food, there is a chance of food entering into trachea and causes choking.
3. As a result irritation and inflammation takes place in the respiratory tract.
4. So we are advised not to talk while eating.

10th Class Biology Textbook Page No. 30

Question 14.
What is the role of diaphragm and ribs in respiration? Are both active in man and woman?
Answer:

1. Diaphragm and ribs are helpful the chest cavity to increase or decrease the volume for inspiration and expiration in respiration.
2. Diaphragm plays a major role in men and ribs play a major role in mechanism of respiration.

10th Class Biology Textbook Page No. 31

Question 15.
What can be concluded from this?
Answer:
All movements of breathing is controlled by nerves leading from the brain.

Question 16.
What happens during the process of breathing?
Answer:
During the process of breathing, the patterns of breathing show a great range for they are coordinated with moment by moment needs of the body for supply of oxygen and removal of carbon dioxide.

Question 17.
Which gas needs to be removed from our body during exhalation? Where does the extra amount of gas come from?
Answer:
Carbon dioxide needs to be removed during exhalation. The extra amount of gas comes from the breakdown of glucose to release energy in the mitochondria. Carbon dioxide gas is released here.

Question 18.
What is the composition of inhaled air?
Answer:
Inhaled air contains oxygen -21%, C09 – 0.03%, Nitrogen – 78%.

Question 19.
When exhaled air is compared with inhaled air, is there any difference in composition?
Answer:
Yes, there is a difference between inhaled air and exhaled air.
The difference is

10th Class Biology Textbook Page No. 32

Question 20.
Why does the amount of oxygen vary between exhaled and inhaled air?
Answer:
Because some amount of oxygen will be utilised during cellular respiration in the body. Hence the difference in amount of oxygen occurs.

Question 21.
What has raised the percentage of carbon dioxide in exhaled air?
Answer:
CO₂ is released from all the cells in the body in respiration and is added to the exhaled air.

10th Class Biology Textbook Page No. 34

Question 22.
Do cells of alveoli or lungs also require oxygen to carry out cellular respiration? Why / Why not?
Answer:

1. Alveoli are made of squamous epithelium tissue which is very thin and elastic
2. Alveoli are so thin that oxygen can pass from air-filled alveoli to R.B.C inside the vessels.
3. Simple squamous epithelial cells function as mediators of filtration and diffusion. As these cells are living tissue they also need oxygen.
4. This is done through the exchange of gases in the alveoli.

Question 23.
After undergoing strenuous exercise we feel pain in muscles, does adequate oxygen reach the muscles?
Answer:
No. Adequate oxygen does not reach the muscles.

Question 24.
What is being formed in the muscles?
Answer:
Lactic acid.

10th Class Biology Textbook Page No. 42

Question 25.
In which set does the colour change faster? Why?
Answer:
In the set which has germinating seeds the colour changes faster. Because CO₂ is formed faster in aerobic respiration.

Think and Discuss

10th Class Biology Textbook Page No. 29

Question 1.
What will happen if the respiratory tract is not moist?
Answer:

1. If the respiratory tract is not moist the dirt particles in the inhaled air will not be removed from air in the nasal cavities and reaches lungs and create problems to lungs.
2. The temperature of the inhaled air is brought close to that of the body for the smooth passage in the respiratory tract. If it is dry, it is not possible.
3. If the surface dries out, gas exchange will happen at a very reduced rate since fast moving gaseous oxygen molecules do not efficiently cross the alveoli membrane.
4. The reduced gas exchange is most likely not enough to support blood oxygenation for vital functions of the body.
5. Hence respiratory tract should be moist for smooth exchange of gases.

Question 2.
Are both lungs similar in size?
Answer:
No. Right lung is slightly bigger than left lung.

Question 3.
Why are alveoli so small and uncountable in number?
Answer:

1. The pouch-like air sacs at the ends of the smallest bronchioles are called alveoli.
2. The walls of the alveolus are very thin and they are surrounded by very thin blood capillaries.
3. It is in the alveoli that gaseous exchange takes place.
4. There are millions of alveoli in the lungs. The presence of millions of alveoli in the lungs provides a very large area for the exchange of gases.
5. And the availability of large surface area maximises the exchanges of gases.

AP State Board Syllabus AP SSC 10th Class Biology Important Questions Chapter 3 Transportation.

AP State Syllabus SSC 10th Class Biology Important Questions 3rd Lesson Transportation

10th Class Biology 3rd Lesson Transportation 1 Mark Important Questions and Answers

Question 1.
What happens if blood platelets are absent in blood?
Answer:

1. Blood clotting do not be takes place.
2. So bleeding from the injuries occurs continuously leads to death of the person.

Question 2.
When do you think that our pulse rate goes up?
Answer:
Running, Exercise, Fear, Tension, Climbing up stairs.

Question 3.
List out the apparatus required to conduct root pressure experiments in plant.
Answer:
Clamp, glass tube, strong rubber tube, potted plant.

Question 4.
What happens if there are no valves in the Heart?
Answer:

1. The valves between each atrium and its ventricles are one way valves. They allow the blood to flow from atrium to the ventricles without any hindrance, back flow of blood is stopped.
2. If there are no valves in the heart, blood flow will not be proper, heart can not pump the blood properly into the blood vessels.

Question 5.
What is meant by pulse?
Answer:

1. When we keep our finger at the wrist where the artery is passing into the hand, we feel the pressure of blood moving in it. This is the pulse,
2. The rate of pulse will be equal to the number of heart beats.

Question 6.
Two person’s Blood Pressure is like this:

Whose Blood Pressure is high? What does it indicate?
Answer:
The normal blood pressure is 120/80
The numerator 120 indicates systolic pressure.
The denominator 80 indicates diastolic pressure.
Ramaiah B.P. is 140/80. So he has high blood pressure.

Question 7.
How does lymph differ from blood?
Answer:

1. RBC are present in blood, RBC are absent in lymph.
2. Blood is Red in colour, lymph is colourless.

Question 8.
Name the largest artery in the body.
Answer:
Aorta is the largest artery in the body.

Question 9.
Name the apparatus, shown in the figure below.

Answer:
Sphygmomanometer.

Question 10.
List out the materials you have used to observe the goat heart in your laboratory.
Answer:

1. Freshly collected specimen of goat’s heart
2. Soda straws
3. Used pen refils
4. The sharp and long blade
5. Tray
6. A jug of water
7. Dissection scissors
8. Forceps
9. Gloves

Question 11.
Name any two valves present in human heart.
Answer:

1. The valve that is present between left atrium and left ventricle is mitral valve or bicuspid valve.
2. The valve that is present between right atrium and right ventricle is the tricuspid valve.

Question 12.
Siri injured while playing, and the blood is flowing continuously from the wound, what may be the reason for this?
Answer:
a) Vitamin – K is helpful for clotting of blood. Perhaps Siri might be suffering from a deficiency of Vitamin – K. So, blood is flowing continuously from the wound,
b) He may be suffering from thalassemia.

Question 13.
Prepare two questions, which you ask the doctor to know more details about high blood pressure.
Answer:
a) How can we know that we have high blood pressure?
b) What are the adverse affects of high blood pressure?
c) How can we prevent high blood pressure?
d) What diet should you prescribe for high BP patients?

Question 14.
What is the number of heart beats in new born babies.
Answer:
Number of heart beats in new born babies are 100-150 times.

Question 15.
What is the number of heart beats in well trained adult athletes.
Answer:
Number of heart beats in well trained adult athletes are 40 – 60 times.

Question 16.
Where is heart located in our body? How is it protected?
Answer:
Heart is located in between the lungs and protected by rib cage.

Question 17.
What is the size of our heart?
Answer:
The size of our heart is approximately size of our fist.

Question 18.
What is the shape and structure of heart?
Answer:
The heart is a pear shaped structure, triangle in the outline, wider at the anterior end and narrower at the posterior end.

Question 19.
What protects the heart from shocks?
Answer:
The space between the two layers of pericardial membrane (Pericardium) is filled with pericardial fluid which protects the heart from shocks.

Question 20.
What divides the heart into four parts?
Answer:
The heart is divided into four parts by grooves.

Question 21.
What are the blood vessels that supply blood to muscles of the heart?
Answer:
The blood vessels that supply blood to muscles of the heart are coronary vessels.

Question 22.
Which is the largest artery in the body?
Answer:
Aorta is the largest artery in the body.

Question 23.
Which artery supplies deoxygenated blood from heart to lungs?
Answer:
Pulmonary artery supplies deoxygenated blood from heart to lungs.

Question 24.
What are the two veins that collect blood from anterior parts and posterior parts of the body?
Answer:
Superior venacava (pre-caval vein) collects blood from anterior parts of the body and inferior venacava (Post-caval vein) collects blood from posterior parts of the body.

Question 25.
Who studied the veins in the leg and what did he notice?
Answer:
In 1574, an Italian doctor, Girolamo Fabrici, studied the veins in the leg and noticed the presence of valves in them.

Question 26.
What are the very fine blood vessels that connect smallest arteries and veins called?
Answer:
The very fine blood vessels that connect smallest arteries and veins are called capillaries.

Question 27.
Who discovered the capillaries in the wings of bats ?
Answer:
Marcello Malpighi discovered the capillaries (1661) in the wings of bats.

Question 28.
On which day the human heart starts beating during the embryonic development?
Answer:
The human heart starts beating around 21st day during the embryonic development.

Question 29.
What is cardiac cycle ?
Answer:
One contraction and one relaxation of atria and ventricles is called one cardiac cycle.

Question 30.
One cardiac cycle completes in approximately?
Answer:
The whole process of one cardiac cycle completes in approximately in 0.8 seconds.

Question 31.
The cardiac cycle includes?
Answer:
The cardiac cycle includes an active phase systole and a resting phase the diastole of atria and ventricles.

Question 32.
The number of heart beats in Blue Whale?
Answer:
The number of heart beats in Blue Whale are 7 times.

Question 33.
The number of heart beats in the bird Coaltit?
Answer:
The number of heart beats in the bird coaltit are 1200 times.

Question 34.
What is Edema?
Answer:
Edema is the condition in which the lower part of the legs will be swollen due to overnight journey in sitting position without moving legs.

Question 35.
What is single circulation of blood?
Answer:
If blood flows through heart only once in one circulation is called single circulation, e.g: Fish.

Question 36.
What is double circulation of blood?
Answer:
If the blood flows through the heart twice in one circulation is called double circulation, e.g : Frog and man.

Question 37.
What is lymph?
Answer:
Lymph is the substance that contains blood without solid particles.

Question 38.
What is tissue fluid?
Answer:
To supply nutrients to the cells the liquid portion of the blood with nutrients flows out of the capillaries. This is called tissue fluid.

Question 39.
What is serum?
Answer:
The light yellow coloured liquid portion after formation of the blood clot is called serum.

Question 40.
In which organism does protoplasm show Brownian movements?
Answer:
Protoplasm shows Brownian movements in Amoeba.

Question 41.
Which organisms use sea water for transportation?
Answer:
The poriferans/parazoans like sponges use sea water for transportation.

Question 42.
Which takes up the function of digestion and transportation of nutrients to each and every cell of the body in cnidarians?
Answer:
Gastrovascular cavity takes up the function of digestion and transportation of nutrients to each and every cell of the body in cnidarians. e.g: Hydra and Jelly fish.

Question 43.
In which animals is the digestive system highly branched and digested food to all the cells is supplied?
Answer:
The digestive system is highly branched and supplies digested food to all the cells in platyhelminthes.

Question 44.
Which takes up the function of collection and distribution of materials in Nematyhelminthes?
Answer:
The Pseudocoelom takes up the function of collection and distribution of materials in Nematyhelminthes.

Question 45.
What are the first Eucoelomate animals?
Answer:
The Annelids are the first eucoelomate animals.

Question 46.
Which have developed the heart, a pulsative organ to pump the blood?
Answer:
The Arthropods have developed the heart, a pulsative organ to pump the blood.

Question 47.
What is lymphatic system?
Answer:
Lymphatic system is a parallel system to venous system which collects tissue fluid from tissues and transports it to the venous system.

Question 48.
What is open type of circulatory system?
Answer:
The transportation system which supplies nutrients to the tissues directly is called open type of circulatory system, e.g: Arthropods, many molluscs and lower chordates.

Question 49.
What is closed type of circulatory system?
Answer:
The transportation system where the blood takes the responsibility of delivering the materials, which flows in the blood vessels is called closed type of circulatory system, e.g : Annelids, echinoderms, cephalopod molluscs and all the higher animals.

Question 50.
Where do doctors measure blood pressure in human beings?
Answer:
Doctors measure blood pressure in the upper arm artery.

Question 51.
What is the instrument used to measure blood pressure?
Answer:
The instrument used to measure blood pressure is a sphygmomanometer.

Question 52.
What is the normal blood pressure of a human being?
Answer:
The normal blood pressure of a human being is 120/80.

Question 53.
What is Hypertension? (OR)
What is high blood pressure?
Answer:
In some people high blood pressure more than the normal blood pressure of 120/80 is present during rest period. Such a condition is called Hypertension usually called high B.P.

Question 54.
Which vitamin plays an important role in coagulation of blood?
Answer:
Vitamin – K plays an important role in the coagulation of blood.

Question 55.
What is Haemophilia?
Answer:
Due to genetic defect, the blood may not coagulate or clot. This type of defect is called haemophilia.

Question 56.
What is Thalassemia?
Answer:
Thalassemia is a group of inherited blood disorders characterized by mild to severe anaemia caused by haemoglobin deficiency in the red blood cells.

Question 57.
Why is the blood pressure more in arteries than veins?
Answer:
The arteries receives blood directly from the heart hence the pressure is more in arteries than veins.

Question 58.
Why is the wall of left ventricle thicker than that of the right ventricle?
Answer:
The left ventricle pumps blood to more distant parts of the body such as from heart to fingers and toes. Hence the wall of left ventricle is thicker than that of the right ventricle.

Question 59.
How is xylem situated in the root and the stem?
Answer:
In the root the xylem tissue is situated towards the exterior while in the stem it is arranged in bundles towards the center.

Question 60.
Which process plays an important role in the absorption of water by root hairs?
Answer:
Osmosis plays an important role in the absorption of water by root hairs.

Question 61.
What is transpiration?
Answer:
Evaporation of water in the form of water vapour through stomata of leaves is called transpiration.

Question 62.
What are the different types of nutrients required for plant growth?
Answer:
Micronutrients and macronutrients are the different types of nutrients required for plant growth.

Question 63.
Which tissue transports water to all the other parts of the plant?
Answer:
Xylem tissue transports water to all the other parts of the plant.

Question 64.
Which tissue transports food to all the other parts of the plant?
Answer:
Phloem tissue transports food to all the other parts of the plant.

Question 65.
What is the amount of water that an oak tree can transpire per day?
Answer:
The amount of water that oak tree can transpire per day is 900 liters.

Question 66.
How many liters of water does a fully grown maize plant transpire in a week?
Answer:
Fully grown maize plant transpires 15 liters per week.

Question 67.
How does the opening and closing of stomata take place?
Answer:
When guard cells are filled with water, the walls of the cells are pulled away and the pores open up. When the water content is low the walls of guard cells collapse and close the stomata.

Question 68.
The rate of transpiration depends upon?
Answer:
The rate of transpiration depends on temperature, humidity, wind velocity, soil, water content, etc.

Question 69.
How does the transpiration help the leaf of a plant?
Answer:
Transpiration helps to keep the leaf surface at a lower temperature than the surrounding air.

Question 70.
What is translocation?
Answer:
The transport of soluble product of photosynthesis through phloem is known as translocation.

Question 71.
Why are the artery walls very strong and elastic?
Answer:
Because they are carrying blood away from the heart to every cell of the body tissue and are doing with a lot of pressure. So the walls are thick to enable it to do its job and are elastic.

Question 72.
The lumen size is bigger in vein when compared with artery. Why?
Answer:
Veins are generally large in diameter, carry more blood volume and have thinner wall in proportion to their lumen.

Question 73.
What is the function of the Gastrovascular cavity?
Answer:
Digestion and transportation of nutrients to each cell of the body in cnidarians is the function of Gastrovascular cavity.

Question 74.
What is the meaning of the word lymph in Latin?
Answer:
In Latin, lymph means water.

Question 75.
It is advisable to take limited food in journey? Why?
Answer:
The body movements will be less in the journey. So taking little food is good for easy digestion.

Question 76.
It is advised to take low amounts of salt in food? Why?
Answer:
Salt (sodium) levels will be more in accumulated water at the time of edema. If salt is not reduced in food the salt levels increase in blood and cause other problems in the body. Hence it is advised to take low amounts of salt in food.

Question 77.
When do you think that our pulse rate goes up?
Answer:
Our pulse rate goes up after jogging, running, strenuous exercise, during fear, anxiety, etc.

Question 78.
Sometimes barks of the tree damaged more than a half, even though tree is alive. How is this possible?
Answer:
In the root the xylem tissue is situated towards the exterior while in the stem it is arranged in bundles towards the center. Hence if the barks of the tree are damaged more than a half there is no obstruction to flow of water, the tree is alive.

Question 79.
Which animals do great damage particularly to beech and sycamore?
Answer:
Grey squirrels do great damage particularly to beech and sycamore.

Question 80.
Which predators are encouraged by foresters to keep down the population of voles and rabbits that damage plants?
Answer:
Foxes, Badgers, Hawks, Owls are encouraged by foresters to keep down the population of voles and Rabbits that damage plants.

Question 81.
What is Rhesus factor?
Answer:

1. It is an antigen occuring on the red blood cells of many humans (85%) and same other primates known as the rhesus factor.
2. It also plays major role in transfusion.
3. Rhesus factor was first discovered in rhesus monkeys.

10th Class Biology 3rd Lesson Transportation 2 Marks Important Questions and Answers

Question 1.
Using the data collected by you, from internet and other sources, make a report on coagulation of blood.
Answer:
The process of clotting of blood from the blood vessels when a person injured is known as blood coagulation. Blood platelets starts the process of blood coagulation. When the blood flows out, the platelets release an enzyme called “Thrombokinase”. Thrombokinase acts on prothrombin converting it into thrombin.
Thrombin acts on another substance called fibrin that is present in dissolved state converting it into insoluble fibrin. The blood cells entangle in the fibrin fibres forming the clot.

Question 2.
By the information provided by scientist William Harvey, complete the following table.

Answer:

Question 3.
How did you prepare a match-stick Stethoscope in your school?
Answer:

1. Take a shirt button.
2. Insert a matchstick into the button.
3. Place it on wrist.
4. We have to observe the movements of the matchstick.

Question 4.
After reading the functions of lymphatic system, what precautions you would suggest to your elders about Edema ?
Answer:

1. Should not sit in the same position for long time.
2. Should move legs frequently.
3. Should sit in a up right position.
4. Take low salt diet.
5. Do exercise regularly.
6. Protect themselves from extreme temperature changes.

Question 5.
What will happen if pulmonary veins are tied with a thread?
Answer:
The pulmonary vein brings oxygenated blood from the lungs and open into left auricle. If the pulmonary veins are tied with a thread the oxygenated blood will not supply to the heart and body parts from the lungs. Hence the person will die because of lack of oxygen.

Question 6.
Suggest some precautions to avoid cardiac problems.
(OR)
What changes would you like to bring in your life style to avoid cardiac problems?
Answer:
I will bring following changes in my lifestyle.

1. Avoid heavy fat food and junk food.
2. Try to spend stress free life as stress leads to cardiac problems.
3. I will do regular physical exercise or work to keep myself fit.
4. Keep away from bad habits like smoking and alcohol consumption.
5. After 40 years, yearly twice I will consult cardiologist.

Question 7.
Read the Para:
Platelets play major role in the coagulation of blood. Whenever the blood flows from the wound, platelets releases the enzyme called Thrombokinase. Thrombokinase acts on another substance present in the blood called prothrombin converting it into thrombin. Thrombin acts on another substance called fibrin that present in the dissolved state converting it into insoluble Fibrin fibers. The blood cells entangle in the Fibrin fibers forming the clot.
Now, answer the following questions:
a) What happens if blood is not coagulated?
Answer:
If blood is not coagulated, it bleeds continuously from the wound, some times it leads to death of a person.

b) Which enzyme helps in the coagulation process?
Answer:
The enzyme thrombokinase helps in coagulation process.

c) How is Thrombin formed?
Answer:
Thrombokinase acts on another substance present in blood called prothrombin converting it into thrombin.

d) What do we call the yellow coloured fluid appear after the formation of the clot?
Answer:
The yellow coloured fluid appear after the formation of the clot is SERUM.

Question 8.
Observe the following table and answer the questions.

i) What is meant by Cardiac cycle?
Answer:
One contraction and one relaxation of atria and ventricles is called one Cardiac Cycle.

ii) Write relation between the weight of the heart and heart beat.
Answer:
If the heart weight increases the rate of heart beat decreases and if the heart weight is less and the rate of heart beat is more.

Question 9
Look at the following table and answer the questions.

a) Who is healthy person? Why?
b) Who is suffering from hypertension? What are the reasons?
Answer:
a) Kiran is a healthy Person as he has normal blood pressure of 120/80 mm/Hg.
b) Rajesh is suffering from hypertension. Reasons for hypertension are eating foods with high salt, obesity, smoking habits, alcohol consumption, lack of physical exercises and hereditary reasons.

Question 10.
What would happen if transpiration doesn’t occur in plants?
Answer:
i) Transpiration is a process by which plants lose excess of water in the form of water vapour, which in turn returns to environment and comes down as rain. Forests have the highest rainfall due to transpiration.

ii) If plants do not transpire, it affects rainfall.

Question 11.
Neelima conducted an activity on her friends and got the following results.

i) What is the relation between heart beat and pulse rate?
Answer:
Heart beat rate is equal to pulse rate.

ii) Why is the heart beat rate more after jogging?
Answer:
In the jogging muscles need more oxygen to produce high energy. To supply this oxygen heart beat is increased after jogging.

Question 12.
A person is injured while playing on the ground. Blood is flowing continuously. What might be the reasons?
Answer:
In this case blood is not clotting. Because

1. He may be suffering from ‘Haemophilia’.
2. Blood platelets are less in number.
3. He may suffer from vitamin-K deficiency.
4. Enzyme ‘Thrombokinase’ may not release.

Question 13.
What questions do you pose to your teacher to understand ‘blood clotting’?
Answer:

1. What is coagulation?
2. How does blood coagulate?
3. What are the factors responsible for coagulation?
4. What happens if coagulation occurs in blood vessels?
5. Which substance prevents coagulation of blood in blood vessels?
6. Which vitamin is required for coagulation of blood?
7. What happens if coagulation of blood does not occur when we meet with accidents?
8. Which cells present in blood help in coagulation of blood?

Question 14.
Where are the valves located in human heart? Write their names.
Answer:
Valves present in human heart.

Question 15.
What happens if there are no valves in veins?
Answer:

1. If the valves are absent in veins blood will not flow in unidirection and flows backward too.
2. Blood will not be supplied to heart properly.
3. Bulging of veins may takes place.

Question 16.
Which items do you take into consideration to explain the differences of arteries and veins?
Answer:
I would like to consider the following items to explain the difference between arteries and veins. They are thickness of walls, valves, capacity to retain shape when blood is absent, direction of blood flow, pressure in the vessels, type of blood transported, type of blood carried by pulmonary artery and type of blood carried by pulmonary vein.

Question 17.
When you know the heart pumping method is circulatory system, which issue do you remember particularly? What’s the reason for that?
Answer:
The heart beats faster during and after an exercise remembered by me. Because at that time our body needs more energy under these conditions. The faster breathing of heart pumps blood more rapidly to the body organs which supplies more oxygen to the body cells for rapid respiration to produce more energy. That is a great job for heart muscle.

Question 18.
Classify different types of blood vessels in humans. On what bases do you classify blood vessels?
Answer:

1. There are three types of blood vessels called arteries, veins and capillaries present in humans.
2. These blood vessels are classified on the basis of thickness of walls, valves, capacity to retain shape when blood is absent, direction of blood flow, pressure in the vessel, type of blood transported, type of blood carried by pulmonary artery or vein.

Question 19.
Anil fell down while going to school, got knee injury, started bleeding. After sometime he wondered on seeing blood clot? Why did blood clot?
Answer:
Blood clotting normally occurs when there is damage to blood vessel. Platelets immediately begin to combine to the cut edges of the vessel and release chemicals to attract even more platelets. A platelet clot is formed and the external bleeding stops.

Question 20.
How is the human heart protected from shocks or injuries?
Answer:
Protection of human heart:

1. Heart in human beings is protected in different ways.
2. It is enclosed in a double layered, transparent thin membrane called pericardium.
3. The space between the inner and outer layers is called pericardial space.
4. This space is filled with a fluid called pericardial fluid.
5. Pericardium and pericardial fluid protect the heart from physical shocks.
6. It is also protected by ribcage or chest cavity.

Question 21.
Describe the blood vessels that carry away blood from human heart.
Answer:

1. The rigid vessels called arteries which originate from the heart supply blood to various organs in the body.
2. From the upper part of the left ventricle a thick blood vessel called Systemic Aorta arises. It supplies oxygenated blood to the body parts.
3. From the upper part of the right ventricle pulmonary artery arises. It supplies deoxygenated blood to the lungs.
4. A pair of coronary arteries (vessels) carry oxygenated blood to the muscles of heart.

Question 22.
What is a mitral valve? What is its function?
Answer:

1. Mitral valve: The valve present between left atrium and vertricle is known as mitral valve.
2. Function: It allows blood to flow from left atrium to left ventricle. It also known as bicuspid valve.

Question 23.
Describe the external features of heart.
Answer:

1. Heart is a hollow organ. It is situated slightly towards left side in the middle of the chest cavity.
2. It is made up of cardiac muscle.
3. It is pear shaped wider at the anterior and narrower at the posterior end.
4. It is protected by ribcage and vertebral column.
5. Generally it is the size of the one’s fist.

Question 24.
What are the differences between right ventricle and left ventricle?
Answer:

Question 25.
How can Thalassemia major be treated?
Answer:

1. Thalassemia major should be diagnosed as early as possible in order to prevent growth restriction, thin bones and infections in the first year of life.
2. If Hb is less than 70% or the child shows signs of poor growth and development.
3. Regular transfusion is the treatment of choice.
4. This can usually be achieved by carrying out transfusions of concentrated red blood cells at intervals of every three to four weeks.
5. Today Thalassemia major can be cured by stem cell transplantation.

Question 26.
Why is double circulation necessary in human beings? Or Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Answer:

1. In humans the right side and left side of the human heart is useful to keep deoxygenated and oxygenated blood from mixing.
2. The separation of oxygenated and deoxygenated blood ensures a highly efficient supply of oxygen to the body.
3. It is useful in case of humans which constantly require energy to maintain their body temperature constant.

27. In some people blood does not coagulate. Give the reasons for it.
(OR)
What is Haemophilia? What are the causes for it?
Answer:

1. Normally the blood that comes out from a wound clots in 3 – 6 minutes. But in some people due to vitamin K deficiency it takes more time to clot.
2. Due to genetic defect blood may not coagulate. This type of defect is called Haemophilia.
3. Haemophilia is a common disorder in the children who have born from the marriages between very close relatives.

10th Class Biology 3rd Lesson Transportation 4 Marks Important Questions and Answers

Question 1.
What is coagulation of blood ? Explain the process of coagulation in brief.
(OR)
Collect information from internet and other sources about blood clotting and prepare a note on it.
Answer:
When the blood vessel is injured, the platelets collect at the site of the injury and form a clot and prevents further loss of blood. This is known as coagulation of blood. Process of Coagulation:

1. When the blood flows out from injuries, the platelets release an enzyme called thrombokinase.
2. Thrombokinase acts on another substance present in the blood called prothrombin converting it into thrombin.
3. Thrombin acts on another substance called fibrin, that is present in dissolved state converting it into insoluble fibrin.
4. The blood cells entangle in the fibrin fibers forming the clot.
5. The fibrin fibers are attached to the edges of the wound and pull them together.

Question 2.
B₁, B₂, B₃, A, C, D, E, K are the symbols of vitamins. Classify these vitamins based on solubility and diseases due to vitamins deficiency.

Answer:

Question 3.
Ramu got injured while playing Kabaddi. His blood clotted within 6 minutes. Write the procedure involved in it.
Answer:

When the blood flows out from injuries, the platelets release an enzyme called thrombokinase.
2) Thrombokinase acts on inactive prothrombin and converts into thrombin.
3) Thrombin converts the soluble fibrinogen into insoluble fibrine fibers.
4) The blood cells entangle in the fibrin fibers forming the clot.
(or)

Question 4.
Read the para:

In the heart, superior vena cava and inferior vena cava opened into right atrium. The pulmonary veins bring blood from the lungs and open into left atrium. The valve present between the right atrium and right ventricle is referred as ‘Tricuspid valve ’. The valve present between the left atrium and left ventricle is refferred as Bicuspid valve. A major blood vessel that originate from right ventricle is Pulmonary Aorta. The valves present at the region of Pulmonary Aorta are called pulmonary valves. A major blood vessel originates from left ventricle is Systemic Aorta. The valves present at the region of Systemic Aorta are called systemic valves.

Now, fill the table with the above information.

Answer:

Question 5.
Study the given paragraph and answer the questions.

When you cut yourself the blood flows out of the wound for only a short time. Then the cut is filled with a reddish solid material. This solid is called a blood clot. When blood flows,out, the plate lets release an enzyme called thrombokinase. Thrombokinase acts on another substance present in the blood called pro – thrombin converting it in to thrombin. Thrombin acts on another substance called fibrinogen that is present in dissolved state converting it in to insoluble fibrin. The blood cells entangle in the fibrin fibers forming the clot.

A) Which blood cells are helpful in blood coagulation?
B) Which enzyme is responsible for blood coagulation? When is it released?
C) How does soluble fibrinogen in blood convert into insoluble fibrin fibers?
D) What will happen, if blood doesn’t coagulate when wound occurs?
Answer:
A) Blood platelets
B) Thrombokinase is responsible for blood coagulation. When the blood flows out the platelets release this enzyme thrombokinase.
C) Thrombin converts fibrinogen in blood into insoluble fibrin.
D) Blood bleeding from the injuries occurs continuously leads to death.

Question 6.
i) Label the parts of heart in the diagram below:
ii) Which blood vessel brings deoxygenated blood from all parts of the body?
iii) Which chamber(s) of the heart have more thick walls? Why?
Answer:
i)

1. Artery to left arm
2. Pulmonary artery
3. Left atriu
4. Left artrioventricular valve
5. Inferior vena cava
6. Right atrio – ventricular valve
7. Right atrium
8. Superior vena cava

ii) Superior vena cava / Inferior vena cava
iii) Ventricles; to pump blood.

Question 7.
Describe the internal structure of heart with a neat labelled diagram.
(OR)
What is called pumping station in human body? Explain its structure with suitable diagram.
Answer:

1. Heart is called pumping station in human body.
2. Internally heart is divided into four parts by grooves.
3. Two upper parts are called atria, and two lower parts are called ventricles.
4. The two atria are separated from each by inter-atriolar septum and the right and left ventricles are separated from each other by inter-ventricular septum.
5. The inter-atriolar septum and inter-ventricular septum prevent mixing of deoxygenated blood in the right side of the heart with oxygenated blood in the left side of the heart.
6. The walls of the ventricles are relatively thicker than atrial walls.
7. The largest artery is the aorta which arises from the left ventricle supplies blood to all the body parts except lungs.
8. Pulmonary artery that arises from the right ventricle carries deoxygenated blood to lungs.
9. The right atrium and right ventricle are connected to each other by right atrioventricular aperture.
   
10. The left atrium and left ventricle are connected to each other by left atrioventricular aperture.
11. Tricuspid valve guards the right auriculoventricular aperture and mitral valve or bicuspid valve guards the left atrioventricular aperture.
12. Blood from the anterior parts of the body is collected by superior venacava which opens into right atrium.
13. Blood from the posterior parts of the body is collected by inferior venacava or post caval vein which also opens into right atrium.
14. Coronary arteries supply blood to the muscles of the heart whereas coronary veins collect blood from the heart. It also opens into right atrium.

Question 8.
Write about the valves, their positions, their functions in human heart. How many blood vessels are attached to heart? Write about their positions and functions.
Answer:
Valves and their positions in Human Heart:

1. The valve present in between right atrium and right ventricle is Tricuspid valve.
2. The valve present in between left atrium and left ventricle is Bicuspid valve.
3. The valve present at the region of pulmonary arota is called Pulmonary valves.
4. The valves present at the region of systemic arota is called systemic valves.

Blood vessels attached to the heart, their positions and functions:

1. The blood vessels found in the walls of the heart are coronary vessels which supply blood to muscles of the heart.
2. From the upper part of the left ventricle aorta arises it supplies oxygenated blood to the body parts.
3. From the upper part of the right ventricle pulmonary artery arises which supplies deoxygenated blood to the lungs.
4. The vein which is right side of the heart is superior venacava.
5. The vein which is coming from the posterior part of the heart is inferior venacava which collects blood from posterior part of the body.

Question 9.
Read the table and answer the following questions.

i) In which phylum, blood vessels are first formed?
Answer:
Blood vessels first formed in phylum annelida.

ii) In which phylum, organisms have haemoglobin in their blood?
Answer:
Organisms in phylum annelida have haemoglobin in plasma of blood,

iii) In which phylum, digestive system helps in transportation?
Answer:
The digestive system in the phylum cnidarian helps in transportation,

iv) Why do arthropods have open circulatory system?
Answer:
In arthropods blood vessels are absent, sinuses are present. So they have open circulatory system.

Question 10.
Write a short note on Human Lymphatic System and its functions.
Answer:

1. Lymphatic system consists of lymph capillaries, lymph vessels, lymph nodes and lymph glands.
2. To supply nutrients to the cells (tissues), the liquid portion of the blood with nutrients flows out of the capillaries. This is called tissue fluid.
3. To transport the tissue fluid into the main blood stream, a separate system called lymphatic system is present.
4. Lymph is the vital link between blood and tissues by which essential substances pass from blood to cells and excretory products from cells to blood.
5. Lymph is the substance that contains blood without solid particles.
6. From intercellular spaces, lymph goes into lymphatic capillaries.
7. Lymphatic capillaries join to form large lymph vessels which finally open into larger veins.
8. Lymph flows only in one direction, that is from tissues to heart through veins.
   Functions of Lymph:
   a) Lymph carries digested and absorbed fats from small intestine to different tissues of the body.
   b) It helps in removing waste materials from the cells in the body to drain into blood.
   c) Lymph protects cells in the tissues from infection.

Question 11.
Explain the process of coagulation of blood.
Answer:

1. When the blood flows out from injuries, the platelets release an enzyme called thrombokinase.
2. Thrombokinase acts on another substance present in the blood called prothrombin converting it into thrombin.
3. Thrombin acts on another substance called fibrin, that is present in dissolved state converting it into insoluble fibrin.
4. The blood cells entangle in the fibrin fibers forming the clot.
5. The fibrin fibers are attached to the edges of the wound and pull them together.

Question 12.
Observe the given diagram. Which type of cardiac cycle does it indicate? Explain the process that happens here.
Answer:

1. It indicates double circuit circulation. It includes pulmonary circulation and systemic circulation.
2. Here blood flows through the heart twice for completing one circulation. Hence it is called double circulation.
3. In this circuit deoxygenated blood from organs of body is collected into the right auricle and then sent into right ventricle. From right ventricle blood is pumped to the lungs. In the lungs blood is oxygenated and is returned to the left auricle by pulmonary vein. This circulation is known as pulmonary circulation.
4. In systemic circulation the oxygenated blood from the left auricle is pumped into the left ventricle. From the left ventricle blood is pumped into the systemic aorta. This aorta supplies blood to various organs of the body.

Question 13.
In human body “A” is a pumping organ. From lungs blood vessel “B” with oxygen¬ated blood enters upper “C” part of left chamber of the organ. When “C” chamber contracts blood flows into “D” lower left chamber. “D” chamber contracts blood is pumped to all parts of the body except lungs through blood vessel E. Deoxygen¬ated blood from body parts is collected by blood vessel “F’ and opens upper “G” right chamber. This chamber contracts blood flows “H” lower chamber. Lastly “H” contracts De-oxygenated blood sent to lungs by blood vessel “I”.
a) “A” represents what organ?
b) (i) B (ii) E (iii) F and (iv) I are what blood vessels? Write their names.
c) (i) C (ii) D are what chambers?
d) (i) G (ii) H are what chambers? Write their names.
Answer:
a) Heart
b) i) B – Pulmonary vein
ii) E – Systemic aorta
iii) F – Superior or Inferior venacava
iv) I – Pulmonary artery
c) i) C – Left atrium
ii) D – Left ventricle
d) i) G – Right atrium
ii) H – Right ventricle

Question 14.
Which blood vessels bring blood to human heart and from where?
Answer:

1. There are three large veins that bring blood to heart from all the body parts.
2. From upper parts of the body (from head and neck) blood is collected by superior venacava.
3. The inferior venacava brings deoxygenated blood from lower parts of the body like abdomen, hands and legs. These caval veins open into right auricle.
4. The third vein called pulmonary vein brings oxygenated blood from lungs and open into left ventricle.
5. In addition to these, veins called coronary veins bring deoxygenated blood from the walls of the heart. They also open into right auricle.

Question 15.
Give an account of valves in the human heart. (OR)
Write about different valves present in human heart and their uses.
Answer:

1. Heart has valves which allow the flow of blood only in one direction and prevents its flow in backward direction. Valves are held in position by tough connective tissue called chordaetendinae.
2. Right auriculo – ventricular aperture is controlled by a tricuspid valve which allows the blood flow from right auricle to right ventricle.
3. Left auriculo – ventricular aperture is provided with bicuspid valve which controls the blood flow from left auricle to left ventricle.
4. At the origin of pulmonary aorta in the right ventricle three half moon shaped or semilunar valves present which allow the blood to flow from right ventricle into pulmonary aorta.
5. At the origin of systemic aorta in the left ventricle there are three semilunar aortic valves which allow the blood flow from left ventricle into the aorta.

Question 16.
What is pulmonary circuit ? Explain it with the help of a block diagram.
Answer:

1. In pulmonary circulation the deoxygenated blood collected by superior and inferior venacava enters right auricle.
2. From right auricle the deoxygenated blood enters right ventricle from there it send to the lungs by pulmonary artery.
3. From lungs pulmonary vein carries oxygenated blood into left auricle. From here blood enters into left ventricle.
   

Question 17.
What is systemic circuit? Explain it with the help of a block diagram.
Answer:

1. In systemic circulation oxygenated blood from left atrium is pumped into left ventricle.
2. From left ventricle the blood is carried to different parts of the body through systemic Aorta.
3. The deoxygenated blood from all the body parts is collected into right auricle through inferior and Superior Venacava.
   

Question 18.
Complete the following table with the details of arteries and veins.

Answer:

Question 19.
How did multicellular animals solve their problem of transport of substances?
(OR)
Write about the evolution we see in the transport system of multicellular animals.
Answer:

1. Early in the evolution, multicellular animals have solved their problem of transport by dissolving majority of the required substances in water and then transporting to various body parts. Ex: Sponges to Heimenthes.
2. Later on the evolution, special fluids like blood and lymph have been developed for the transport of substances within the body. Ex: Insects.
3. In primitive animals, necessary force for transport of these fluids was given by contraction and relaxation of body muscles. These fluids were circulated with in the body cavity. Ex: Earthworm.
4. Later on evolution, for circulation of fluids a closed circulatory system was developed. This consists of heart, blood vessels and blood. Ex: Amphibians, reptiles, aves and mammals.

Question 20.
What is blood pressure? How is it measured?
Answer:

1. The pressure with which the blood flows in the blood vessels is known as blood pressure.
2. Blood pressure is measured in the upper artery.
3. There are two pressure readings.
4. One measures the strongest pressure during the time blood is forced out of the ventricles. This is called systolic pressure.
5. For a healthy young adult it will be 120 mm of Hg.
6. The second reading is taken during the rest period, as the ventricles refills with blood. This is called diastolic pressure.
7. The diastolic pressure will be 80 mm of Hg.
8. Doctors measure the blood pressure with a device called sphygmomanometer.

Question 21.
How do you prove that transpiration is done through stomata of a leaf? (OR) Describe an experiment to show that water is lost from the stomata of leaf.
Answer:
Aim: To prove that transpiration is done through stomata present in the leaves.
Required material: A healthy potted plant, a polythene cover, water.
Procedure: Take a well watered plant. Tie a polythene cover to one of its small branch and keep it in the sunlight. After sometime observe the inner sides of the polythene cover.
Observation: It is observed that the inner sides of polythene cover is moist with water drops.
Inference: The excess of water from the plant evaporates through stomata of leaves into the atmosphere. This process is called Transpiration.

Question 22.
Explain the process of absorption of water by the root hair and movement of water in xylem.
Answer:

1. The soil water is an extremely dilute solution of salts, more dilute than that of the cell sap in the root hair.
2. Therefore water will pass into the vacuole of the root hair by osmosis.
3. The entry of water dilutes the contents of the root hair vacuole so that it becomes weaker than its neighbour.
4. Therefore water passes into the neighbouring cell which in turn becomes diluted, finally water enters the xylem vessels.
5. As there are vast numbers of root hairs and root cells involved, a pressure in the xylem vessels develops which forces the water upwards.
6. This total pressure is known as root pressure which is responsible for movement of water in xylem.
7. The water which passed into the xylem vessels forms a continuous system of tubes through root and stem into the leaves.
8. The evaporation of water creates the main pull from above root pressure gives a variable and minor push from below.

Question 23.
Explain the process of transport of mineral salts and water in plants.
(OR)
Explain how root pressure and transpiration pull help in the transport of mineral salts and water in plants.
Answer:

1. Xylem tissue transports water and mineral salts in plants.
2. Xylem vessels and tracheids of root, stem and leaves are interconnected to form a continuous system of water and minerals conducting channels to each part of the plant.
3. The cells of root hair present in the soil absorb water from the soil by osmosis.
4. The entry of water dilutes the contents of the root hair vacuole so that it becomes weaker than its neighbour.
5. Therefore water passes into the neighbouring cell which in turn becomes diluted, finally water enters the xylem vessel.
6. This creates a column of water that is steadily pushed upward, called root pressure.
7. Root pressure is not enough to push water and dissolved minerals to leaves in the tall trees.
8. There is a continuous loss of water through stomata of the leaves in the form of water vapour. This process is called transpiration.
9. The water lost due to transpiration is taken up from the xylem vessels and tracheids in the leaves.
10. This loss of water during transpiration creates a suction pressure which pulls water from the xylem cells of roots.
11. This results in enhanced absorption and upward movement of water and dissolved minerals from roots to the leaves due to transpiration.
12. At night when stomata are closed root pressure has an effect on transportation of water.
13. Transpiration pull is the major force in the movement of water and dissolved minerals in the xylem during daytime.

Question 24.
Write an experiment to illustrate the conduction of sugars by phloem.
(OR)
How are sugars conducted by phloem in plants?
Answer:

1. Experiments to illustrate the conduction of sugars by the phloem have been done by removing a ring of bark from a shoot to expose the wood.
2. Remove all tissues from the cambium outwards including the phloem.
3. After a few days, when the tissues above and below the ring were analyzed.
   
4. It was shown that food had accumulated above the ring but was not present below it.
5. If it is left for sometime, the stem increases in thickness immediately above the ring, but no growth occurred below it.
6. So, any damage to the phloem all around the stem will prevent food from passing down to the roots and the tree will eventually die.

Question 25.
Write about the changes in the evolution of transport system in animals.
Answer:

1. In Amoeba due to Brownian movements nutrients and oxygen are distributed throughout the protoplasm equally.
2. The parazones like sponges use sea water for transportation. Sponges create their own currents by beating of flagella that are present in their body.
3. Cnidarians developed blind sac like gastro vascular cavity, which has taken up the function of digestion and transportation of nutrients, e.g.: Hydra and jelly fish.
4. In platyhelmenthes, the digestive system supplies digested food to all the cells directly, excretory system collects wastes from each cell individually.
5. In animals belonging to Nematyhelmenthes the pseudocoelom has taken up the function of collection and distribution of materials.
6. In Annelids, animals have developed a pulsative vessel to move the fluid and the transporting medium is blood.
7. In Arthropods have developed a pulsative organ to pump the blood. The blood flows in the tissues, directly supplying the nutrients to the tissues.
8. Transportation system which supplies nutrients to the tissues directly is called open type of circulatory system, e.g. : Arthropods, many molluscs and lower chordates.
9. The other type of transportation system where the blood takes the responsibility of delivering the materials, which flows in the blood vessels.
10. Such type of closed circulatory system is present in annelids, echinoderms, cephalopod molluscs and all the higher animals.

Question 26.
Briefly explain about Thalassemia disease.
(OR)
What is thalassemia disease ? What is the main cause for it?
Answer:

1. Thalassemia is a group of inherited blood disorders characterized by mild to severe anaemia caused by haemoglobin deficiency in the red blood cells.
2. In individuals with thalassemia, the production of the oxygen carrying blood pigment haemoglobin is abnormally low.
3. There are two main types of thalassemia: alpha thalassemia and beta thalassemia.
4. In each variant a different part of the haemoglobin is defective.
5. Individuals with mild thalassemia may have symptoms such as anaemia, enlarged liver and spleen; increased susceptibility, slow growth, thin and brittle bones and heart failure.

Question 27.
What are the facts known about Thalassemia?
Answer:

1. Thalassemia is a serious inherited Blood disorder.
2. 4.5% of world population (250 million) suffering with Thalassemia minor.
3. There are over 35 million Indians are carriers of the abnormal Gene for Thalassemia.
4. It is estimated that about 1,00,000 infants are born with major Haemoglobinopathies every year in the world.
5. 10,000 – 12,000 Thalassemic children are born every year in our country.
6. Survival depends upon repeated blood transfusion and costly medicines.
7. Thalassemia can be prevented by awareness, pre marital or pre conceptual screening followed by ante-natal diagnosis is required.

Question 28.
What is the effect of Rhesus factor in childrens if Rh⁺ person marries Rh^– woman?
Answer:

1. If a Rh⁺ man marries a Rh^– woman, some of the children are likely to be RlT.
2. If a child is Rh⁺ some of its blood will leak into its mother’s circulation and cause antibodies to form in her blood.
3. If the mother has more children the amount of antibodies in her blood often increases with each pregnancy, and in some instances the antibodies in her blood may pass into the baby’s blood in sufficient quantities to produce very serious anaemia and even death.
4. When such cases occur, the baby is given a complete transfusion soon after birth sp that the baby’s blood is replaced by blood containing no antibodies to the rhesus factor.

Question 29.
What are the components of the circulatory system in human beings? What are their functions?
Answer:

1. The circulatory system or transport system in human beings consists of heart, blood and blood vessels.
2. Heart is a pumping organ to push blood around the body. It receives deoxygenated blood from body organs and pump it to lungs for oxygenation.
3. Heart receives oxygenated blood from lungs and sends it to different body parts.
4. Blood is a fluid connective tissue consists of a fluid medium known as plasma in which white blood cells, red blood cells and platelets are suspended.
5. Blood transports food, carbondioxide and nitrogenous wastes in dissolved form.
6. Red blood cells transports oxygen.
7. Platelets present in blood help in coagulation of blood.
8. Blood pushed by the heart flows in blood vessels called arteries and also comes back to the heart in the blood vessels called veins.

Question 30.
Draw T.S. of flow of blood in arteries and veins. Write flow of blood in between them.
(OR)
Write the differences between T.S. of artery, T.S. of vein and T.S. of blood capillary.
Answer:

1. In arteries, oxygenated blood flows. Arteries supply oxygenated blood to all body parts except lungs. Pulmonary artery supplies deoxygenated blood from right ventricle to lungs.
2. Veins collects deoxygenated blood from all body parts into the right atrium. Pulmonary vein brings oxygenated blood from lungs into left atrium.
3. Blood capillaries are the microscopic vessels that connect smallest arteries and veins.

Question 31.
What was the classical experiment conducted by William Harvey to demonstrate movement of blood in veins ?
(OR)
How do you repeat the classical experiment to demonstrate the movement of blood in veins?
Answer:

1. In early 17th century William Harvey conducted an experiment to demonstrate the movement of blood in veins.
2. Tie a tornquit just above the elbow of a person, whose blood vessels are prominent in the hand.
3. Ask that person to hold the fist with a piece of cloth rolled in the hand. Now the blood vessels can be seen more prominently.
4. Find undivided blood vessel, where we have to work for the next few minutes.
5. At the end of the vessel farthest from the elbow apply steady pressure, so as to close its cavity.
6. Now apply pressure from elbow towards the palm slowly and observe the changes in the blood vessels.
   

Question 32.
What are the structural and functional differences of arteries, veins and capillaries?
Answer:

1. The walls of arteries are made up of muscle fibers and are elastic. When the blood enters with a pressure into the arteries then walls will stretch and this enables the arteries to withstand the increase in the pressure without bursting.
2. Veins are closer to the skin and contain valves. They are made of connective tissue called Tunica adventitia or Tunica externa. Middle layer has bands of smooth muscle called Tunica media. Generally veins are thin, lined internally with endothelial cells Tunica intina.
3. Blood capillaries are microscopic vessels made of single layer of cells. They allow diffusion of various substances. They establish continuity between arterioles and venules. Capillaries is the Latin word which means “hair” because they were as thin as the finest of hairs.
   

Question 33.
What is the cardiac cycle? Explain it with the help of a diagram.
(OR)
Draw a diagram of different stages of systole and diastole. Explain.
Answer:
One contraction and one relaxation of atria and ventricles is called one cardiac cycle.

1. We start with imagination that all the four chambers of the heart are in relaxed state.
2. Blood from venecava and pulmonary veins enters the right and left atria respectively.
3. Now the atria contract and forcing the blood to enter into the ventricles.
4. On ventricular contraction due to pressure the blood moves into the aorta and pulmonary artery.
5. When the valves between the atria and ventricles are closed we can hear the sharp sound of the heart lub.
6. When the ventricles start relaxing, the pressure in the ventricles is reduced. The blood which has entered the arteries tries to come back into the ventricles. The valves which are present in the blood vessels are closed to prevent backward flow of blood into the ventricles.
7. Now we can listen to a dull sound of the heart dub. The atria filled up with blood and are ready to pump them into the ventricles.
8. The sequential events in the heart which are cyclically repeated are called cardiac cycle. It includes an active phase systole and a resting phase the diastole of atria and ventricles.
   

Question 34.
What is hypertension? How is it caused? Mention the preventive steps to be taken.
Answer:

1. Blood flows in the blood vessels with a specific pressure called Blood Pressure (B.P.) In healthy individuals, the normal B.P. is 120/80.
2. The numerator (120) represents Systolic pressure and the denominator (80) represents Diastolic pressure.
3. Blood pressure is measured by the doctors by an instrument called SPHYGMOMANOMETER.
   
4. However in some people blood pressure is very high more than normal B.P. This condition is called Hypertension.
5. One of the reasons for hypertension is the blocking of arteries by cholesterol. Constant stress and strain for a long time, improper functioning of kidneys, smoking and alcohol consumption are the reasons for high B.P.
6. Hypertension can be prevented by diet control moderate exercise, avoiding stress and strain, avoiding
   alcohol consumption and smoking.

AP State Board Syllabus AP SSC 10th Class Biology Important Questions Chapter 5 Coordination.

AP State Syllabus SSC 10th Class Biology Important Questions 5th Lesson Coordination

10th Class Biology 5th Lesson Coordination 1 Mark Important Questions and Answers

Question 1.
“Plants respond to stimuli.” During a project work on it, from which plants do you collect information and record it?
Answer:
a) Mimosa Pudica (Touch me not plant) b) Sunflower c) Cucumber d) Bittergourd

Question 2.
Write two points about insulin from the information you collected from internet. (OR)
Write two sentences about insulin hormone using the data collected from your school library.
Answer:

1. Insulin is secreted by islets of longerhans of pancreas gland.
2. Deficiency of insulin results in diabetis mellitus.

Question 3.
You have performed the activity of Seed Germination in a glass jar in your school lab. You might have observed the growth of shoot and root. What information did you record regarding the shoot growth after a week if the glass jar is tilted and plant kept horizontally.
Answer:

1. More auxins collects on light falling side of the stem.
2. Cells on that side grow faster and make the stem bends towards light due to phototropism.

Question 4.
Write the functions of Spinal-cord from the information collected from your school library and from internet.
Answer:

1. Carries the information to the brain from the lower parts of the body.
2. It carries the information from brain to body parts.
3. It plays a key role in the reflex actions.
4. It acts as relay centre.

Question 5.
Where do we find Cerebro-spinal fluid? Mention one of its functions.
Answer:
The space between the inner layers of brain is filled with fluid called cerebrospinal fluid (CSF). It serves as a shock-absorbing medium and protects the brain against shocks, jerks along with the meninges and cranium.

Question 6.
Mention at least one activity done at school to show involuntary reflexes.
Answer:
Knee-jerk.

Question 7.
Write the name of the nerve given in the following diagram and write its function.
Answer:
The given diagram is the sensory Neuron. They are also called Afferent nerves.
Function: They carry messages towards central nervous system (Brain or spinal cord) from nerve endings on the muscles of different sense organs, that sense the change in surroundings.

Question 8.
Identify the given part in the diagram and write its use.
Answer:
i) Synapse.
ii) It is a functional region of contact between two neurons where infromation from one neuron is transmitted to another neuron.

Question 9.
Name the part of the brain that maintains the equilibrium.
Answer:
The part of the brain that maintains the equilibrium is cerebellum.

Question 10.
Who discovered the first plant hormone auxin?
Answer:
The first plant hormone auxin was discovered by F.W. Went.

Question 11.
What was the belief of Greeks?
Answer:
The Greeks believed that all functions of the body were controlled by the brain, since damage to that organ produced remarkable changes in behaviour.

Question 12.
How many types of nerves are present in human body? What are they?
Answer:
Nerves are classified mainly into three types.

1. Afferent neurons
2. Efferent neurons
3. Association neurons.

Question 13.
What are Afferent neurons?
Answer:
Afferent neurons: Nerves which carry messages towards the central nervous system (Spinal cord or brain) from sense organs are called afferent neurons. These are also called sensory nerves.

Question 14.
What are efferent neurons or nerves?
Answer:
Efferent neurons: Nerves which carry messages from the central nervous system to parts that shall carry out the response are called efferent neurons. They are also called as motor nerves.

Question 15.
What are association nerves?
Answer:
The nerves, which link together the afferent and efferent nerves are called association nerves.

Question 16.
What is stimulus?
Answer:
Stimulus is a thing or event that causes a specific functional reaction in an organ or tissue.

Question 17.
What is response?
Answer:
Response is a effect of a change in the environment of the organism or signals of change or stimuli.

Question 18.
What does rapidity of response indicate?
Answer:
Rapidity of response indicates an efficient communication system linking those parts that pick up stimuli to those that trigger a response.

Question 19.
How are responses bring about?
Answer:
Responses are brought about by rapid changes in some muscle.

Question 20.
According to Galen a Greek physiologist how many kinds of nerves are present in body?
Answer:
According to Galen, nerves are of two kinds. They are 1) for sensation and 2) for action.

Question 21.
What are the major parts of neuron?
Answer:
The major parts of neuron are cell body or cyton, dendrites and axon.

Question 22.
What are the two types of projections that extend from cell body?
Answer:
The two types of projections that extend from cell body are dendrites and axon.

Question 23.
What is synapse?
Answer:
Synapse is the functional region of contact between two neurons.

Question 24.
Synapses are mainly found in?
Answer:
Synapses are mainly found in the brain, spinal cord and around the spinal cord.

Question 25.
What are reflexes?
Answer:
The responses to a stimulus on which we do not have control are called reflexes or reflex action.

Question 26.
What is the importance of reflex action?
Answer:
Reflex action save us from painful or dangerous stimuli.

Question 27.
How many types does the nervous system is divided?
Answer:
Nervous system is divided into two types. They are central nervous system and peripheral nervous system.

Question 28.
What are the parts of central nervous system?
Answer:
The parts of the central nervous system are brain and spinal cord.

Question 29.
What are the three major divisions in brain?
Answer:

1. Forebrain
2. Mid brain and
3. Hind brain.

Question 30.
What are the parts present in fore brain?
Answer:
The parts present in fore brain are cerebrum and diencephalon.

Question 31.
What are cranial nerves? How many cranial nerves are present?
Answer:
Nerves originate from brain are called cranial nerves. 12 pairs of cranial nerves arise from brain.

Question 32.
How many pairs of spinal nerves are present?
Answer:
31 pairs of spinal nerves are present.

Question 33.
Which is called peripheral nervous system?
Answer:
Peripheral nervous system consists of nerves arising from the brain and spinal cord. 12 pairs of cranial nerves from brain and 31 pairs of spiral nerves from spinal card together called peripheral nervous system.

Question 34.
What is autonomous nervous system?
Answer:
The peripheral nervous system that controls the involuntary actions of the body is called autonomous nervous system.

Question 35.
What are the systems involved in control and coordination in animals?
Answer:
The systems involved in control and coordination in animals are nervous system and endocrine system.

Question 36.
The hormone insulin is secreted by?
Answer:
The hormone insulin is secreted by Islets of Langerhans of pancreas gland.

Question 37.
Give examples for endocrine glands.
Answer:
The examples for endocrine glands are pituitary gland, thyroid gland, parathyroid, adrenal, hypothalamus, pancreas, thymus, testes and ovaries.

Question 38.
The nervous system that regulates heart beat, breathing, etc., is?
Answer:
The nervous system that regulates heart beat, breathing etc., is autonomous nervous system.

Question 39.
What is thigmotropism?
Answer:
The directional growth movement of a plant part in response to the touch of an object is called thigmotropism.

Question 40.
Name the receptors of taste and smell.
Answer:
The receptor of taste is gustatory receptor and that of smell is olfactory receptor.

Question 41.
What is reflex action? Give examples.
Answer:
Reflex action is a quick involuntary response to a stimulus by an effector.
e.g: Withdrawing our hand from hot object, blinking of eyelids when a moving object approaches eye.

Question 42.
What is the difference between a reflex action and walking?
Answer:
Reflex action is an involuntary action whereas walking is a voluntary action.

Question 43.
Which part of the brain maintains posture and equilibrium of the body?
Answer:
The part of the brain that maintains posture and equilibrium of the body is cerebellum.

Question 44.
How do we detect the smell of agarbathi or incense stick?
Answer:
We detect the smell of agarbathi or incense stick when the olfactory receptors in the nose detect smell by sending nerve impulses to the olfactory centre of the brain.

Question 45.
What is target tissue?
Answer:
Tissues or organs on which hormones act are called target tissues or organs.

Question 46.
What are the main cells of the nervous system?
Answer:
The main cells of the nervous system are the neurons. Besides the neurons the nervous system also consists of glial cells.

Question 47.
What is phototropism?
Answer:
The movement of a plant part in response to light is called phototropism.

Question 48.
What is geotropism?
Answer:
The movement of a plant part in response to gravity is called geotropism.

Question 49.
What is chemotropism?
Answer:
The movement of a plant part in response to chemical stimulus is called chemotropism.

Question 50.
What is hydrotropism?
Answer:
The movement of a plant part in response to water is called hydrotropism.

Question 51.
How many nerve cells does human nervous system consist of?
Answer:
Human nervous system consists of about 100 billion cells.

Question 52.
What is reflex arc?
Answer:
The structural and functional unit that carries reflex action is called reflex arc.

Question 53.
The three layers covering the brain are called?
Answer:
The three layers covering the brain are meninges.

Question 54.
What are the functions carried out by cerebrum?
Answer:
Cerebrum is a seat of mental abilities, controls thinking, memory, reasoning, perception, emotions and speech.

Question 55.
What are the functions of cerebellum?
Answer:
Cerebellum maintains posture, equilibrium and muscle tone.

Question 56.
Which parts are present in hind brain?
Answer:
Cerebellum and medulla oblongata are the parts present in hind brain.

Question 57.
What is the function of feedback mechanism?
Answer:
The function of feed back mechanism is to regulate the production and release of hormones in the body.

Question 58.
Thyroxine hormone controls the body’s function like?
Answer:
Thyroxine hormone controls body’s function like general growth rate and a metabolic activity.

Question 59.
What are voluntary actions? Give examples.
Answer:
The movements under the control of the conscious mind are called voluntary actions. Example : Kicking foot ball, lifting bucket of water, reading book, running, walking, playing, eating, etc.

Question 60.
What are involuntary actions? Give examples.
Answer:
The movements which are not under the control of the conscious mind are called involuntary actions. Example : Respiration, circulation, digestion.

Question 61.
What is nerve impulse?
Answer:
The information passing through a neuron in the form of electrical and chemical signals is called nerve impulse.

Question 62.
What are phytohormones?
Answer:
The hormones present in the plants are called phytohormones.

Question 63.
The phytohormone Abscisic acid is responsible for?
Answer:
Closing of stomata and seed dormancy are caused by the phytohormone Abscisicacid.

Question 64.
What are the functions of auxins?
Answer:
Auxins are responsible for cell elongation and differentiation of shoots and roots.

Question 65.
What is the speed of nerve transmission?
Answer:
Nerve transmission from stimulus to a response can occur at a maximum speed of about 100 meters per second.

Question 66.
What is vasomotor?
Answer:
Vasomotor refers to actions upon a blood vessel which alter its diameter.

Question 67.
What are dorsal and ventral root ganglion?
Answer:
The dorsal root and ventral root ganglions are the regions very close to the spinal cord in which the nerve cell bodies lie. Dorsal root ganglion is present on the dorsal side of spinal cord and ventral root ganglion is present on the ventral side of the spinalcord.

Question 68.
What is the function of dorsal root ganglion?
Answer:
The dorsal root ganglion carries messages of sensation toward brain or spinal cord.

Question 69.
What is the function of ventral root ganglion?
Answer:
The ventral root ganglion carry the instructions from the brain or spinal card to muscles.

10th Class Biology 5th Lesson Coordination 2 Marks Important Questions and Answers

Question 1.
What questions will you ask a doctor to know about endocrine glands?
Answer:

1. Which glands are known as endocrine glands?
2. Where can we find endocrine glands in our body?
3. What do you call chemical substances secreted by Endocrine glands?
4. Which endocrine gland is attached to the brain?
5. What are the functions of endrocrine glands?
6. What will happen if endocrine glands are absent?

Question 2.
How do you feel when you realize that plants respond to the stimuli of their surroundings?
Answer:

1. It is very interesting and amazing to observe trophic and nastic movements of plants in our surroundings.
2. For example, the bending of shoots of creepers towards light kept near the window.
3. The plant roots always grow downwards.
4. The creepers like cucumber and bittergourds develops tendrils in response to contact or touch.
5. Butterflies fluttering around the flowers for nectar.

Question 3.
What will happen if a plant is placed near the window of your classroom? What is this process called?
Answer:

1. The plant bends towards the sun light and grow.
2. This process is called phototropism.

Question 4.
How do you appreciate the role of Spinal-cord in reflex actions?
Answer:

1. Spinal cord responds very fast and immediate.
2. The nerve impulses are transmitted very fast at the speed of 100 m/min.
3. So that we are protected from many dangerous situations.
4. So I really appreciate and amazing reflex actions of the spinal cord.

Question 5.
Read the following table:

Answer the following questions:
i) Which hormone is released at the time of emotions?
Answer:
Adrenaline

ii) Name the hormone responsible for the development of Secondary sexual characters.
Answer:
Estrogen, Testosteron.

Question 6.
Ram met with an accident. After that he lost the capacity to walk in straight manner and cannot smell anything. Which part of the brain got damaged in the above cases?
Answer:

1. The forebrain and hind brain of Ram might have been damaged.
2. The olfactory lobes of the forebrain are concerned with sense of smell. Here, Ram lost the sense of smell anything. Hence the olfactory lobes of forebrain got damaged.
3. The cerebellum of hind brain maintains posture, equilibrium and muscle tone.
4. After accident, Ram lost the capacity to walk in a straight manner and hence, I predict that cerebellum of Ram also got damaged.

Question 7.
What questions will you ask a doctor to know about pancreatic gland?
Answer:

1. Where is pancreas located?
2. Why is it called a mixed gland?
3. What is the role of pancreas as an endocrine gland?
4. Name the disorders occur to pancreas.

Question 8.
What is the role of Adrenalin in controlling emotions?
Answer:
Adrenalin increases rate of heart beat, causes rise in blood sugar, dilation of coronary artery and dilation of pupil of the eye.

Question 9.
What is the significance of the adrenal gland in the human body?
Answer:
Adrenal gland secrets adrenaline. It helps in

1. Increase heart beat rate
2. Rise in blood sugar
3. Dilation of the coronary artery
4. Dilation of pupil of the eye.

Question 10.
Write the difference between hormone and enzyme.
Answer:

Question 11.
Observe the following table and answer the questions.

i) Name the phytohormone in the table.
ii) Name the hormone which influences growth rate in humans.
Answer:
i) Auxin
ii) Thyroxine.

Question 12.
What questions you will ask a neurologist on function of brain?
Answer:

1. How does alcohol cosumption affect the brain?
2. Which part of brain is responsible for creativity?
3. How do we get fits ? 4) How do we get paralysis?
4. What kind of food should we take to increase?

Question 13.
Label a, b, c, d in the diagram given below and write their functions.
Answer:
a) Sensory Neuron/-Afferent Neuron: These carry messages towards the central nervous system.
b) Motor Neuron /- Efferent Neuron: These carry messages from central nervous system to body parts
c) White Matter
d) Effector Muscles: Respond to stimuli.

Question 14.
Prepare a table showing tropic movements in plants in response to stimuli.
Answer:

Question 15.
Explain two tropic movements with suitable examples.
Answer:

1. Phototropism: Response of plant to light cite example is called phototropism.
   Ex: sunflower
2. Geotropism: Response of a plant to gravitational force Ex: root growth of plant
3. Hydrotropism: Response of root to water availability in the soil.
   Ex : Plants which are growing very close to rocks and walls.
4. Thigmotropism: Response to make contact or touch is called Thigmotropism.
5. Chemotropism: Response to chemical is called chemotropism (Stigma secretes sugary substances)

Question 16.
Write two voluntary functions and two involuntary functions you have observed in your body.
Answer:
a) Examples for voluntary functions:

1. Cleaning the table
2. Playing on the keyboard.

b) Examples for involuntary functions :

1. Salivating when food is kept in the mouth
2. Closing of eyes when bright light is focussed.

Question 17.
Plants show tropic movements in different situations. Give examples.
Answer:

1. Movement of individual parts of plants is possible when they are subjected to external stimuli. This type of response is called tropism or tropic movement.
2. The response of a plant to light is called phototropism. Respond of plants for gravity is called geotropism. Movement of plant towards water is called hydrotropism. The type of response by plants to make contact or touch is called thigmotropism. The response of plants to chemicals is called chemotropism.
3. Pollen grains respond to this stimulus as pollen tubes grow to reach the ovule for fertilization.

Question 18.
Divide the following into groups. Walking, blinking of eye lids, heart beat, laughing, digestion of food and reading. How do you divide them into groups?
Answer:
These can be divided into voluntary actions, involuntary actions and reflex actions.
Voluntary actions: Walking, laughing, reading
Involuntary actions: Digestion of food, heart beat
Reflex actions: Blinking of eye lids

Question 19.
What are ganglia?
Answer:

1. Ganglia or neural ganglia are the structures located in the peripheral nervous system (for example beside the spinal column or near viscera) made of concentration of neuron bodies.
2. Examples of neural ganglia are the ganglia that concentrate cell bodies of sensory neurons in the dorsal roots of the spinal cord and the ganglia of the myenteric plexus responsible for the peristaltic movements of the digestive tube.

Question 20.
Write a brief note on the functioning of sympathetic nervous system.
Answer:

1. This part of the autonomous nervous system increase the activity of an organ as per the need.
2. For example, during running there is an increased demand for oxygen by the body.
3. This is fulfilled by an increased breathing rate and increased heart rate.
4. The sympathetic nervous system works to increase the breathing rate and the heart rate.

Question 21.
Explain briefly about the action of parasympathetic nervous system.
Answer:

1. This part of the autonomous nervous system decrease the activity of an organ and it has calming effect.
2. During sleep, the breathing rate and also the heart rate slows down.
3. This is facilitated by the parasympathetic nervous system.
4. It can be said that the parasympathetic nervous system helps in conservation of energy.

Question 22.
Why are some patients of diabetes treated by giving injections of insulin?
Answer:

1. Insulin is produced by Islets of Langerhans of pancreas.
2. Insulin regulates the level of glucose in the blood.
3. Deficiency of insulin results in disease called ‘diabetes’.
4. Such diabetic patients are given injections of insulin so that the sugar or glucose level in the blood can be controlled.
5. Insulin is now produced in large quantities for the treatment of human sufferers from ‘sugar diabetes’.

Question 23.
What is chemotropism? Explain it with suitable example.
Answer:

1. Response of a plant towards chemicals is known as chemotropism.
2. If we taste the carpel of a flower, it is sweet.
3. Butterflies flutter on flowers for nectar.
4. Ripen stigma secretes sugary substance.
5. This chemical substance stimulates the pollen grain which falls on the stigma.
6. Pollen grains respond to this stimulus as pollen tubes grow to reach the ovule for fertilization.

Question 24.
What are plant growth substances? Give examples.
Answer:

1. Plant growth substances are the chemical (organic) substances which are produced in plants and act at minute concentration on growth and other phisiological functions of plants.
2. There are five major types of plant growth substances. They are auxins, Gibberellins, cytokinins, Ethylene and Abscisic Acid.

Question 25.
What is ethylene? Explain its action.
Answer:

1. Ethylene is a gaseous growth inhibiting substance.
2. Ethylene causes ripening of the fruits.
3. It modifies the growth of the plant by inhibiting stem elongation.
4. It accelerates abscission of leaves, flowers and fruits.

Question 26.
What is Apical dominance?
Answer:

1. In some plants main stem grows by the activity of terminal bud without giving any branches.
2. It means the activity of lateral buds is suppressed and this phenomenon of suppression of the growth of lateral buds by terminal bud is called Apical dominance.

Question 27.
What happens at the synapse between two neurons?
Answer:
At synapse, in between the end of one axon and end of another dendrite electrical impulse sets off the release of some chemicals (neurotransmitter). These chemicals cross the gap or synapse and reach to dendrites of the next neuron and start electrical impulse there.

10th Class Biology 5th Lesson Coordination 4 Marks Important Questions and Answers

Question 1.
i) This diagram belongs to which system of the body?
Answer:
Human nervous system

ii) Name the parts A and B.
Answer:
A. Cerebellum
B. Medulla oblongata

iii) The part ‘C is endocrinal gland. This is called master gland. What is the name of this gland?
Answer:
Pituitary gland

iv) Which part in this diagram is useful to solve problems and puzzles?
Answer:
Cerebrum

Question 2.
Name the important parts of the brain and write the functions of fore-brain.
(OR)
Write in a tabular form the different parts of human brain and their functions.
Answer:

1. Brain has the following divisions.
   1. Fore brain – Cerebrum, diencephalon
   2. Mid brain – Optic lobes.
   3. Hind brain – Cerebellum, medulla.
2. Functions of the various parts of the brain.
   

   Parts of the brain	Functions
   Cerebrum	i)    Seat of mental abilities, controls thinking memory, reasoning, perception, emotions and speech. ii)    Interprets sensations and responds to cold, heat, pain and pressure.
   Diencephalon	i)     Relay centre for sensory impulses, such as pain, temperature and light. ii)    Reflex centre for muscular activities. iii)     Centre for certain emotions such as anger. iv)     Centre for water balance, blood pressure, body temperature, sleep and hunger. v)    The hypothalamus controls the pituitary gland, which functions as the master gland.
   Mid brain	i) It relays motor impulses from the cerebral cortex to the spinal cord and relays sensory impulses from the spinal cord to thalamus, reflexes for light and hearing.
   Cerebellum	i)     Maintains posture, equilibrium and muscle tone. ii)    Coordinates voluntary movements initiated by cerebrum.
   Medulla oblongata	i)     Contains centre for cardiac, respiratory and vasomotor activities. ii)    Coordinate reflexes like swallowing, coughing, sneezing and vomiting.

Question 3.
Observe the following diagram. What does it represent? Explain the process in a flow-chart.
Answer:

Question 4.
Read the following table:

Now, identify the part of the brain which participate in the below situations.

a) Ravi is an intelligent boy. He can remember the things for a long time.
Answer:
Cerebrum

b) The drunken man does not walk properly.
Answer:
Cerebellum

c) Identifies the food items without seeing which are being prepared in the kitchen
Answer:
Olfactory Lobes

d) Naveen lost his money purse while coming to the school. But he is not crying.
Answer:
Diencephalon

e) It is time for lunch.
Answer:
Cerebrum

f) I cannot tolerate this type of heat in the summer.
Answer:
Cerebrum

g) Catching the ball perfectly.
Answer:
Cerebellum

h) There may be a drainage behind the house.
Answer:
Olfactory Lobes

Question 5.
Look at the picture and answer the questions:
a) To which system does the diagram belong ?
Answer:
The diagram belongs to T.S. of Spinal cord (peripheral).

b) What is the name of A, B parts ?
Answer:
A – Dorsal Root,
B – Ventral Root

c) What is ‘C’ ? What is its function ?
Answer:
C – Association neuron
It analyse the information – and send the order (function) through motor neuron to muscle.

d) Through which horn the sensory nerve enters ?
Answer:
Sensory nerve enters through dorsal horn.

Question 6.
Fill the following table related to Endocrine glands.

Answer:

Question 7.
Observe the following table and answer the questions.

a) On what basis the above classification done?
Answer:
Hormones in animals and hormones in plants.

b) From which gland is Adrenalin released?
Answer:
Adrenal gland.

c) Which hormone is responsible for closing of stomata?
Answer:
Abscisic Acid (ABA)

d) What are the functions of Auxins?
Answer:
Cell elongation and differentiation of shoots and roots.

Question 8.

A) What does the given picture represent?
B) Name the parts A, B and C.
C) What carries the nerve impulse to the spinal cord?
D) Wrhat is the function of association neuron?
Answer:
A) The given picture represents
T.S. of Spinal cord (peripheral).
B) A – Dorsal root B – Ventral root C – Association neuron
C) Through dorsal root the nerve impulse reaches the spinal cord.
D) Association neuron analyses the information and sends the order through motor neuron to muscle.

Question 9.
The following table is about parts of brain and their functions. Read it and fill the blanks.

Answer:

Question 10.
Ramya ran away shouting loudly after seeing a snake on the way to school. Arrange the events involved in this situation in the correct order and rewrite it.
i) Brain receives the information, analyses and produces the reponse.
ii) Sensory nerves carry the information from sense organs to brain,
iii) Effector muscles exhibit the response.
iv) Sense organs receive the information from the environment.
v) Motor nerves carry the response from the brain to effector muscles.
Answer:
1-d, 2-b, 3 -a, 4-e, 5-c
d) Sense organs receive the information from the environment.
b) Sensory nerves carry the information from sense organs to brain,
a) brain receives the information analyse and produces the response.
e) Motor nerves carry the response from the brain to effector muscles.
c) Effector muscles exhibit the response.

Question 11.
Observe the following information and answer the following questions.

i) What do we call the hormones that are present in plants?
Answer:
We call phyto hormones which are present in plants.

ii) Name the hormones which are helpful in the growth of the plants.
Answer:
Auxins, gibberellins, cytokinins are helpful in the growth of the plants.

iii) Farmers keep carbide powder in between raw mangoes. What might be the reason? What will be the end result after 3 to 4 days?
Answer:
Carbide release Ethylene, which promotes the fruit ripening. After 3 or 4 days fruits will ripen.

iv) Plants also respond like animals. Do you agree with this statement? Support your answer.
Answer:
Yes, plants also respond like animals. They shut off leaves in summer, germinate in rainy season, blooms according to seasons.

Question 12.
Read the following table and answer the questions given below.

i) Write the importance of glands and hormones.
Answer:
Glands and hormones controls and coordinates various functions of the body with nervous system.

ii) Which hormone is responsible for growth of bone?
Somatotropin is responsible for growth of bone.

iii) What happens if testosterone is not secreted?
Secondary sexual characters in male are not developed if testosterone is absent.

iv) Where does the gland that secretes thyroxine is located?
Thyroid gland which secretes thyroxine is located near the neck.

v) Which glands are common in male and female?
Pituitary, thyroid, adrenal glands, parathyroid and pancreas are common in male and female.

Question 13.
Explain the different types of adaptations in plants with suitable examples.
Answer:

1. Most plants can aerate their roots bj’ taking in the oxygen through the lenticels or through the surface of their root hairs.
2. But plants which have their roots in very wet places, such as ponds or marshes, are unable to obtain oxygen.
3. They are adapted to these water-logged conditions by having much larger air spaces which connect the stems with the roots, making diffusion from the upper parts much more efficient.
4. The most usual adaptation is to have a hollow stem.
5. The problem of air transport is more difficult for trees.
6. An exception is the mangrove tree of the tropics which have aerial roots above the soil surface and takes in oxygen through these roots.

Question 14.
Karthik is suffering from excess sugar in urine and Varun is suffering from repeated dilute urination. What are the reasons for these diseases ? Explain.
Answer:

1. Excess sugar in urine condition is known as diabetes milletus. (sugar diabetes)
2. Repeated dilute urination is known as diabetes insipidus, (diuretic condition)
3. Deficiency of insulin causes high level sugar in the blood and urine. It leads to diabetes milletus (Sugar diabetes).
4. Vasopressin maintains osmotic concentration of body fluids. Deficiency of vasopressin causes excessive repeated dilute urination it is called as diabetes insipidus.

Question 15.
Analyse the following information and answer the questions.

i) Write two functions of Sympathetic Nervous System.
ii) Name two organs that are influenced by Parasympathetic Nervous System.
iii) Name the Nervous system mentioned in the table that increases the blood pressure.
iv) What systems constitute Autonomous Nervous System?
Answer:
i) Dilates pupil, inhibits salivation, relaxes branchi, accelerates heart beat, etc.
ii) Eye, heart, pancreas, etc.
iii) Sympathetic nervous system
iv) Sympathetic and para sympathetic nervous system.

Question 16.
Explain the Phytohormones which control growth in plants.
Answer:
Major plant hormones and their action:

Question 17.
Analyse the table and answer the following questions.

i) Which part of the brain recollects the childhood incidents?
Answer:
Cerebrum.

ii) Write two parts of hind brain.
Answer:
Cerebellum, medulla oblongata.

iii) Name the part of the brain that will not function in drunken person.
Answer:
Cerebellum.

iv) Name the part of the brain that controls involuntary actions.
Answer:
Medulla oblongata.

Question 18.
Write contrasts and comparisons of the style of response in plants and animals to the stimuli.
Answer:

1. Both plants and animals react to various stimuli around them. But the method of responding to stimuli is not similar in plants and animals. .
2. Higher animals respond to stimuli because they have a nervous system and an endocrine system.
3. Plant do not have a well defined nervous or endocrine system. They do have some mechanism of control by means of some chemicals or hormones.
4. Plants can sense the presence of stimuli like light, heat, water, touch, pressure, chemicals, gravity, etc.
5. The hormones present in the plants called phytohormones control response towards the stimuli. Phytohormones coordinate the activities of the plant usually by controlling one or the other aspect of the growth of the plant.

Question 19.
Read the below paragraph and write answers.

There is systematic method in showing response to stimuli. There is different stages in it. First stage starts with the response recognising the changes in outside or inside of the body atmosphere with recognising the stimuli. Transmitting the received information is second stage, analysing that information is third stage and showing correct response to that stimuli is the last stage.

a) What does this information shows?
b) Convert the above information into flow chart.
c) Write about the mechanism that conducts this action.
Answer:
a) It shows the systematic method in showing response to stimuli.

b)

c) Nervous system can sense the changes inside and outside the body through specialised cells called Receptors. This information in the form of small electrical currents is sent to brain and analysed and responses are generated in the nervous system. These responses once again in the form of small electrical currents are conveyed to the appropriate organs such as muscles and glands at a greater speed. Nervous system may store this information for future use.

Question 20.
See the below action. What does it indicate? Explain with an example.
Answer:

1. It indicates the stimulus – response action. This stimulus response can be explained with an example.
2. Suppose a mosquito is biting you on your arm. Mosquito bite is stimulus.
3. The receptor in the skin responds and send the information in the form of electrical impulses through sensory nerve to spinal cord or brain.
4. Brain or spinal cord analyses the information that the mosquito bite is causing pains.
5. The brain or spinal cord sends the message through motor nerve to the effector organ i.e., hand to kill the mosquito.
6. As per the message our hand immediately hits the mosquito and kills it.

Question 21.
Rangaiah is not feeling well. The following table is the results of tests. Analyse the table.

Write answers for the following questions.
i) How can you state that Rangaiah is diabetic?
Answer:
After blood test it was found that level of glucose (Fasting) is 120 whereas the normal range is 60 -100. After lunch the level of glucose in blood of Rangaiah further raised to 220, the normal being between 160 – 180. This shows that Rangaiah is diabetic.

ii) What are the tests to know about Bilirubin?
Answer:
We can know about bilirubin by blood test.

iii) What do you understand from the above report?
Answer:
It shows that Rangaiah is diabetic and his systolic pressure is slightly high. The levels of bilirubin in blood also slightly high, almost normal range. Urine test shows sodium levels are at normal range but 24 hours protein is much higher than normal levels.

iv) What questions do you ask the doctor on the above report?
Answer:

1. What are symptoms shown by Rangaiah as diabetic patient?
2. What are the ways to control sugar in the blood?
3. Which hormone is responsible for raise of glucose in the blood?
4. How sodium maintains blood pressure at normal levels?
5. What is the role of bilirubin in digestion?

Question 22.
What is reflex arc? Write the components of reflex arc and their functions.
Answer:

1. The structural and functional unit that carries out reflex action is called a reflex arc.
2. It consists of five components.
3. They are receptor, a sensory nerve, a association neuron, a motor nerve and an effector organ.
   

   SI. No.	Component of reflex arc	Functions
   1.	Receptor	Receives information and generates impulses.
   2.	Sensory neuron (Afferent)	Carries information from the receptor to the interneurons in the spinal cord.
   3.	Interneuron (Association neuron)	Processes the information and generates responses
   4.	Motor neuron (Efferent)	Carries the information from the spinal cord to the effector organ.
   5.	Effector organ	Receives the information from the efferent neuron and shows the appropriate responses.

Question 23.
What are endocrine glands ? What are their functions?
Answer:
Endocrine glands:

1. Endocrine glands are the ductless glands.
2. They secret complex organic substances called hormones directly into the blood.
3. Hormones are transported through blood to different tissues.
4. Their secretions act as biochemical messengers in the body.

Functions:

1. The hormones secreted by these glands play an important role in co-ordinating various organ systems.
2. Hormones can increase or decrease the metabolism and synthesis of substances like proteins, carbohydrates and lipids.
3. Irregular functioning of these glands may lead to serious diseases.
4. The quantity of hormone required is very minimum (1/10,00,000 gram).
5. A slight increase or decrease may brings out large changes in the target tissue.

Question 24.
How does a nerve impulse travel through the body?
Answer:

1. The information acquired at the dendritic tip of a nerve cell sets off a chemical reaction that creates an electrical impulse.
2. This impulse travels from the dendrite to the cell body and then along the axon to its end.
3. At the end of the axon the electrical impulse sets off the release of some chemicals.
4. These chemicals cross the gap or synapse and start a similar electrical impulse in a dendrite of the next neuron.
5. A similar synapse finally allows the delivery of such impulse from neurons to other cells such as muscles or glands.

Question 25.
How is the brain anatomically divided?
Answer:

1. The cerebrum is divided into two cerebral hemispheres, the right and left.
2. Each hemisphere is made of four cerebral lobes. Frontal lobe, parietal lobe, temporal lobe and occipetal lobe.
3. Each cerebral lobe contains the gray matter and the white matter.
4. The gray matter is the outer portion and is made of neuron bodies, the gray matter is also known as the cerebral cortex.
5. The white matter is the inner portion and it is white because it is in the region where axons of the cortical neuron pass.

Question 26.
What are the divisions of the autonomous nervous system?
Answer:

1. Ganglia near the vertebral column are connected to the spinal cord by nerves.
2. The two divisions of autonomic nervous system are sympathetic nervous system and parasympathetic nervous system.
3. The sympathetic nervous system is formed by the chain of ganglia on either sides of the vertebral column and the associated nerves.
4. The parasympathetic nervous system is formed by the nerves arising from the ganglia of the brain and the posterior part of the spinal cord.
5. These together constitute the autonomous nervous system which is the part of the peripheral nervous system consisting of twelve pairs of cranial nerves and thirty one pairs of spinal nerves.

Question 27.
What is autonomous nervous system? Explain how it controls voluntary functions with an example.
Answer:

1. The peripheral nervous system that controls involuntary functions of the body is known as Autonomous nervous system.
2. It has voluntary control of muscles of some areas of skin and the skeletal muscle.
3. For example when we enter a dark room we can not see anything immediately. Slowly we are able to see the things around us in the room.
4. This is because of increase in diameter of pupil, which allows more light in.
5. When we come out of the dark room into broad day light the diameter of the pupil decreases allowing less light to enter into the eyes.
6. Both these functions occur under the influence of the autonomous nervous system.

Question 28.
What is the master gland in the human body? What are the functions of the hormones it secretes? (OR)
Why is pituitary gland known as master gland? How does it control all the other glands in the body?
Answer:

1. Pituitary gland is known as the master gland of the body as it controls the functions of all the other endocrine glands.
2. It serves as a link between nervous system and endocrine system.
3. The hormones secreted by pituitary gland and their functions are as follows.

Question 29.
What are the differences between the manner in which movement takes place in a sensitive plant and the movement of our legs?
Answer:

1. The stimulus of touch causes the response in a sensitive plant Mimosa pudica.
2. Droping of the leaves takes place due to change in osmotic pressure at the base of the leaf.
3. When the stimulus is over, the osmotic pressure increases causing the leaf to become normal.
4. This is not a growth related movement.
5. It is not connected with the direction of the stimulus.
6. Nerve messages in the form of electrical impulse reaches the leg muscles from the brain.
7. On reaching the leg muscles, the muscles contract causing the movement of the leg.

Question 30.
What is the need for a system of control and coordination of organisms? (OR)
How is control and coordination brought in organisms?
Answer:

1. The various physiological processes in an organism are closely linked and depen¬dent on each other.
2. The linking together of body activities in time and space is called coordination.
3. Without coordination, the activities of the body would be disturbed a lot.
4. For example when eating food at meal, the position of food is recorded by the eyes and as a result of this information the arms are moved to the right place to pick it up with precision and accuracy.
5. As the food is raised to the mouth, the latter opens to receive it. Chewing movements commence and saliva is secreted.
6. At the moment of swallowing, epiglottis closes trachea.

Question 31.
What is the experiment conducted by Charles Darwin and Francis Darwin? What is their conclusion?
Answer:

1. Charles Darwin and his son Francis Darwin performed some experiments on phototropism.
2. They covered the terminal portion of the tip of stem (coleoptile) with a cylinder of metal foil.
3. Exposed the plant to light coming from the side.
4. The characteristic bending of the seedling did not occur.
5. If light was permitted to penetrate the cylinder, bending occurred normally.
6. They concluded that when seedlings are freely exposed to a lateral light some influence is transmitted from upper to the lower part causing the material to bend.

Question 32.
What are the different types of tropisms found in plants?
Answer:

1. The different types of tropisms found in plants are phototropism, geotropism, chemotropism, hydrotropism and thigmotropism.
2. Different stimulus and type of tropism.
   Stimulus Type of tropism
   Light – Phototropism
   Gravity – Geotropism
   Chemical substance – Chemotropism
   Water – Hydrotropism
   Touch – Thigmotropism

Question 33.
Describe the story of invention of insulin. (OR)
Collect the information about insulin from internet and other sources and report on it.
Answer: