Mahesh

AP State Board Syllabus AP SSC 10th Class Biology Solutions Chapter 3 Transportation – The Circulatory System Textbook Questions and Answers.

AP State Syllabus SSC 10th Class Biology Solutions 3rd Lesson Transportation – The Circulatory System

10th Class Biology 3rd Lesson Transportation – The Circulatory System Textbook Questions and Answers

Improve your learning

Question 1.
What is transport system? How does this help to the organism?
(OR)
What is the importance of transport system in the organisms?
Answer:
Transport system: The system which transports the material that is needed to organism is called transport system or circulatory system.
Importance :

1. The system supplies O₂ to parts of the body and also recollects the CO₂ which is excretory product in life process.
2. It supplies food materials to all parts of the body.
3. Hormones can travel through circulatory system.
4. It also helps in regulation of body temperature.
5. It collects the waste materials from parts of the body.
6. It has antibodies to protect our body from pathogens.
7. It helps in maintaining osmatic pressure in the cells.
8. In plant it transports the water through xylem and food materials through phloem.

Question 2.
What is the relationship between blood and plasma?
(OR)
What are the differences between blood and plasma.
Answer:

	Blood	Plasma
1. Definition	Blood is the main body fluid that is responsible for transporting materials.	Plasma is the yellow liquid component of blood and constitutes 55% of the total blood volume.
2. Composition	It has liquid portion called plasma and soiled substances called blood cells.	It contains water (90%), proteins, nutrients, waste products, clotting factors, minerals and hormones.
3. Cells	It has R.B.C, W.B.C and thrombocytes	It does not have any cells.
4. Colour	Red in colour	It has straw – yellow colour.
5. Clotting factors	It has clotting factors known as fibrinogen, prothrombin.	After the clotting plasma turns into serum.

Question 3.
Which type of blood vessels carry blood away from the heart?
(OR)
Which blood vessels carry blood from heart to body parts?
Answer:

1. The rigid vessels are called arteries which originate from the heart and supply blood to various organs in the body.
2. The largest artery is the aorta which arises from the left ventricle supplies oxygenated blood to all parts of the body except lungs.
3. The relatively smaller one is pulmonary artery supplies deoxygenated blood to lungs.
4. A pair of coronary arteries carry oxygenated blood to the muscles of heart.

Question 4.
What are the three main types of blood vessels in the body?
Answer:
The three main types of blood vessels in the human body are:

1. Arteries
2. Veins and
3. Capillaries.

Question 5.
Which is the largest artery in the body? Why is it big in size?
Answer:

1. The Aorta is the largest artery in the body.
2. It is big in size because it has to supply oxygenated blood from heart to various organs in the body from head to fingers and toes.

Question 6.
Which blood vessel carries blood for oxygenation?
Answer:

1. The PULMONARY ARTERY originates in the right ventricle. Outside the heart, it divides into two branches – RIGHT and LEFT PULMONARY ARTERIES.
2. They carry deoxygenated blood to right and left lungs for oxygenation.

Question 7.
Name the structures which are present in veins and lymph ducts and absent in arteries.
Answer:

1. The structures that are present in the veins and lymph ducts are VALVES.
2. These are absent in arteries.
3. They are one-way valves. If the blood moves in the opposite direction, the valves closed and avoid the backward flow of blood in veins and lymph ducts.

Question 8.
Answer:
What is the use of platelets?

1. Platelets help in clotting of blood at the site of injury thus it controls the loss of blood from the wound.
2. When blood flows out, the platelets release an enzyme called THROMBOK1NASE.
3. This acts on another substance called PROTHROMBIN converting it into THROMBIN.
4. Thrombin acts on FIBRINOGEN, converting it into FIBRIN.
5. The blood cells entangle in the fibrin fibres forming the CLOT.
6. 

Question 9.
Write differences between
a) Systole – Diastole
b) Veins – Arteries
c) Xylem – Phloem
Answer:
a) Systole – Diastole:

Systole	Diastole
1. Definition: It measures the amount of pressure that blood exerts on arteries when the heart is contracted.	1. It is the pressure that is exerted when the heart is relaxed.
2. Range: Its normal range is 60-80 mm Hg.	2. Its normal range is 90 – 120 mm Hg
3. Blood pressure: It represents the maximum pressure exerted on the arteries.	3. It represents minimum pressure in the arteries.
4. Blood vessels: They are contracted in this phase.	4. Blood vessels are relaxed in this phase.
5. Ventricles: Ventricles are contracted and they push the blood in this phase.	5. Ventricles are relaxed and filled with blood in this phase.

b) Veins – Arteries:

Viens	Arteries
1. Moves towards the heart.	1. Moves away from the heart.
2. Collects blood from body organs.	2. Distributes blood to the body organs.
3. Blood pressure in veins is low.	3. Blood pressure is high in arteries.
4. Valves are present.	4. Valves are absent.
5. Carry deoxygenated blood, except pulmonary vein.	5. Carry oxygenated blood except pulmonary artery.
6. Veins start in blood capillaries.	6. Arteries end in capillaries.
7. They can be seen subcutaneously.	7. They are deep seated.
8. They collapse when there is no blood in it or cut across.	8. They do not collapse when there is no blood in it.
9. Veins are further divided into venules.	9. Arteries are further divided into arterioles.
10. Veins are usually flattened or collapsed with thin walls.	10. They are round and relatively thick walled.
11. Veins have large lumen.	11. Arteries have small lumen.
12. Veins are bluish in colour.	12. Arteries are reddish in colour.
13. Veins show sluggish movement of blood.	13. Arteries show spurty movement of blood giving pulse.
14. If venous wall is injured, blood comes out, collects in a pool in a small area around vein.	14. If arterial wall is injured, the blood comes out like a fountain in a large area all around the artery.

c) Xylem – Phloem:

Xylem	Phloem
1. In plants water and mineral salts are transported by xylem tissue.	1. In plants food material is transported by phloem tissue.
2. Xylem consists of trachieds, vessels, xylem fibres and xylem parenchyma.	2. Phloem consists of sieve tubes, sieve cells, companion cells, phloem fibres and phloem parenchyma.
3. Only xylem parenchyma is living tissue.	3. Sieve tubes, sieve cells, companion cells and phloem parenchyma are living.
4. Trachieds, vessels, xylem fibres are dead tissues.	4. Phloem fibres are dead tissues.
5. Xylem gives mechanical strength to the plant.	5. Phloem does not give mechanical strength.
6. Conduction of water by xylem is unidirectional i.e., from roots to apical parts of the plant.	6. Food material conduction is bidi­rectional i.e., from leaves to storage organs or growing points and from storage organs to all growing parts of plants.
7. Xylem is star shaped.	7. Phloem is not star shaped.
8. Xylem occupies the center of the vascular bundle.	8. Phloem occurs on outer side of the vascular bundle.
9. Tubular with hard walled cells.	9. Tubular with soft walled cells.

Question 10.
Explain the way how plants get water by osmosis through root hairs.
(OR)
Explain the mechanism of entry of water into root hair by osmosis with the help of a diagram.
(OR)
Explain the process of water entry into the root hair in plants with the help of diagram.
(OR)
In plants, what is the role of root hair in the absorbtion of water and minerals from the soil?
Answer:

1. Root hair plays an important role in absorption of water by osmosis.
   
2. Root hairs grow out into the spaces between the soil particles and that the hairs are surrounded by moisture.
3. The Cytoplasm of the cells in root hairs is called cell sap. It has dissolved salts.
4. The cell sap of the root hair is more concentrated than that of the concentration of salt solution present in the soil.
5. The cell membrane of root hair acts as semi-permeable membrane.
6. It separates the cell sap from the salt solution of the soil.
7. Therefore water passes into the vacuole of the root hair by osmosis.
8. The entry of water dilutes the contents of the root hairs vacuole. So it becomes more diluted than the neighboring cells.
9. Water passes into the neighboring cell which becomes diluted, finally water enters the xylem vessels.
10. As there are vast number of root hairs and root cells involved, pressure in the xylem vessels develops which forces the water upwards.
11. This total pressure is known as root pressure.
12. Root pressure is not the main cause of movement of water in xylem but it is certainly one factor.

Question 11.
What is root pressure? How is it useful to the plant?
Answer:
The pressure exerted by the root hair while absorbing water from the soil is called root pressure.

1. Soil water concentration is more dilute than that of the cell sap in the root hair, therefore water passes into vacuole of the root hair by osmosis.
2. The entry of water dilutes the cell sap so it become more dilute than it’s neighbouring cells.
3. So, water passed into the neighbouring cell which in turn becomes diluted, finally water enters the xylem vessels.
4. As there are vast number of roots hairs and root cells involved, pressure in the xylem vessels develops which forces the water upwards.

Question 12.
Phloem is a food source for some animals. How can you justify the statement ?
Answer:

1. Certain mammals scratching the bark of trees to get the food stored in the phloem, especially during hard winters when food is scarce.
2. Voles do this to young saplings at ground level and rabbits can do much damage to older ones.
3. Aphids absorb so much sugar from the phloem that they cannot assimilate all of it and it passes out of the anus as a sticky syrup called honeydew.
4. Grey squirrels too do great damage particularly to beech and sycamore, and for this reason, in some parts it is impossible to grow these trees as a crop.

Question 13.
Read the given para and name the parts of heart.

We have observed that the heart is divided into four chambers by muscular structure. Any structure that divides two chambers is known as septum. Now let us try to name the septa present in the heart.

A) The septum that divides the two atria can be named as ———-.
Answer: Interatrial septum.

B) The septum that divides the two ventricles can be named as ———-.
Answer: Interventricular septum.

C) The septum that divides the atrium and ventricle can be named as ———-.
Answer: Interatrioventricular septum.

The holes that connect two chambers are called apertures. Let us try to name the apertures which connect the atria and ventricles.

D) The aperture that is connecting the right atrium and right ventricle can be named as ———-.
Answer: Right atrioventricular aperture.

E) The aperture that is connecting the left atrium and left ventricle can be named as ———-.
Answer: Left atrioventricular aperture.

Any structure that closes an aperture, and allows one way movement of materials is called valve. Now let us name the valves that are present in the chambers of the heart.

F) The valve that is present between left atrium and left ventricle can be named as ———-.
Answer: Left atrioventricular valve (Bicuspid or Mitral valve).

G) The valve that is present between right atrium and right ventricle can be named as ———-.
Answer: Right atrioventricular valve (Tricuspid valve).

Question 14.
If the valves in veins of the legs fail to stop the flow of blood, what could be the consequences of this failure?
Answer:

1. If the valves in veins of the legs fail to stop flow of blood, the blood accumulates in the veins and causes swelling or inflammation and more clotting.
2. Clotting can block or slow blood flow through the veins raising the blood pressure and possibly causing more damage.
3. The swelling of the veins also results in varicose veins and spider veins.
4. If varicose veins are untreated for long time, it leads to venous ulceration.

Question 15.
What will happen if cell sap of root hair cells contain high concentration of ions?
Answer:

1. The cell membrane of root hair is a semipermeable membrane. It allows the movement of molecules from low concentration to high concentration.
2. Cell sap of root hair cells contain high concentration of ions and salts than the water present around it in the soil.
3. As a result, water flows from the soil into cell sap of root hairs.
4. From the root hairs water pass from cell to cell by osmosis through the epidermis, root cortex, endodermis and reach the root xylem.

Question 16.
John prepared stethoscope with paper cup and plastic tube. Write down the procedure of preparation.
Answer:
Aim : To prepare a paper cup stethoscope
Apparatus: Three paper cups, plastic tube, scissors, T – bend and thread.
Procedure:

1. Take three paper cups and put a small hole in the bottom of the cups.
   
2. Take a T – bend and arrange it in the back side of one cup as hanging.
3. T – bend is connected to plastic pipe, by the two sides and arrange the paper cups.
4. Put the two upper cups at your ears and bottom one is on the friend’s chest.
5. Now you can hear the sound of heart beat.

Question 17.
How can you prove that the water is transport through the xylem?
Answer:
Aim: To observe the path of water through a plant.
Apparatus: Balsam plant, beaker, Eosine solution, stand.
Procedure:

1. A leafy green shoot of Balsam plant with a transparent stem is placed in Eosine solution (It is red dye resulting from the action of bromine).
   
2. After sometime red streaks appear in the stem and veins of leaves become red.
3. If a transverse section is cut through the root stem and leaf, the tissue that has been stained is xylem tissue.
4. This shows that water moves up the root into the stem and leaves in the xylem tracheids and vessels.
5. The other tissues remain in the same colour.

Conclusion: The xylem tissue is responsible for the upward movement of water through the plant.

Question 18.
What is your inference about experiments with aphids?
Answer:

1. Biologists studied about food transportation in plants with the help of aphids.
   
2. Aphids feed on the plant juices of young stems.
3. Aphid uses its long needle like organ proboscis to extract plant juices from phloem tissue.
4. The proboscis of the Aphid only penetrates up to a phloem sieve tube.
5. It is found experimentally that the contents of the phloem sieve tubes are under slight pressure the fluid slowly comes out from the cut end of the proboscis in the form of drops.
6. These drops were collected and analysed and it contain sugars and amino acids.
7. Aphids absorb so much sugar from the phloem that they cannot assimilate all of it and it excretes out of the body as sticky syrup called honey dew.

Question 19.
Collect information about blood pressure of your school teachers or your neighbours and prepare a report on their health problems.
Answer:

Name of the person	Blood pressure	Health condition
1. Mr. Vijay	120/80	Normal
2. Mrs. Kamala	125/85	Irritation, worried
3. Mr. Raju	140/90	Fear, easily getting anger, high irritation, tiredness.
4. Mrs. Chandu	110/70	Weakness, dizziness, fainting
5. Mr. Rama Rao	140/100	Dizziness, fainting

Question 20.
Draw a block diagram to explain single and double circulation. Write differences between them.
(OR)
What is single circulation and double circulation? Write differences between them with the help of diagrams.
Answer:

1. Single circulation: In a blood circulation the blood passes through the heart only once. This type of circulation is called single circulation and the heart is called single circuit. Ex: Fish
   
2. Double circulation: Blood passes twice through the heart. Once between heart and lungs and second time from heart to body parts. Such circulation is called double circulation and the heart is called double circuit heart.
   Ex: Frog and other higher animals.
   

3. Single Circulation	Double Circulation
   1. Found only in fishes.	1. Found in amphibians, reptiles, birds and mammals.
   2. Blood passes only once through the heart to supply once to the body.	2. Blood passes twice through the heart to supply once to the body.
   3. Only deoxygenated blood passes through the heart.	3. Mixed blood (Oxygenated and deoxygenated) pass through the heart.
   4. It is less efficient in function as the oxygenated blood flows at a low pressure which decreases the rate of oxygen supply.	4. It is most efficient in function as the blood flows at a higher pressure which increases the rate of oxygen supply.

Question 21.
Prepare a block diagram showing from water absorption by roots to transpiration by leaf.
Answer:

Question 22.
What do you want to compare with the transportation in blood vessels in man?
(OR)
What can circulatory system in man be compared with?
Answer:
I compare the circulatory system in man with motor water system in our houses, as below.
Heart – motor                                        Blood vessels – pipes
Blood – water                                         Tank – body parts

Question 23.
How do you feel about transportation of water in huge trees?
(OR)
How do you appreciate the movement of water through xylem in tall trees?
Answer:

1. It is a wonder to see the transportation of water in huge trees.
2. It is surprising how the root pressure and the transportation pull are responsible for the water to reach such heights against the gravitation force.
3. It is a great mechanism evolved in the beautiful plants which give us pleasure.
4. We can really appreciate the creation done by God towards plants and their functions for mankind.

Question 24.
Prepare a cartoon on heart beating.
Answer:

Question 25.
After reading this lesson what precautions you would suggest to your elders about edema?
(OR)
What is edema? How it occurs? What are the precautions required not to be affected with edema?
Answer:
Precautions I would suggest to my elders about edema:

1. Edema is abnormal accumulation of fluid in the interstitium which is located beneath the skin or one or more cavities of the body.
2. Avoid sitting and standing for too long. It promotes fluid flow into the legs and feet.
3. Hence I suggest elders getting up and stretching the legs once in a while travelling long in bus and trains.
4. Leg exercise and feet moving and using leg muscles help pump excess fluids back to the heart.
5. People suffer with edema can keep the legs elevated above the level of heart for 30 minutes a day or 3 or 4 times a day.
6. Massage the edema effected area with firm pressure towards the heart which helps to move the excess fluid away from swelling.
7. Reducing the amount of salt in the diet may prevent swelling problems from reoccuring.
8. Avoid hot baths, hot showers when swelling occurs.

Choose the correct answer.

1. The term cardiac refers to which organ in the body? [ ]
   A) Heart
   B) Vein
   C) Lymph
   D) Capillary
   Answer: A
2. On which side of the human heart is low in oxygen? [ ]
   A) Left ventricle
   B) Right ventricle
   C) Left atrium
   D) Right atrium
   Answer: B & D
3. Which structures of the heart control the flow of the blood? [ ]
   A) Arteries
   B) Veins
   C) Valves
   D) Capillaries
   Answer: C
4. Which of the following opinions is correct? [ ]
   A) Ravi said xylem and phloem cells arranged one upon the other to form a tube like structure.
   B) John said xylem and phloem are not separate tube like structures.
   C) Salma said, xylem and phloem cells connect together to form tube like structure.
   D) Hari said because of its shape they said to be tube like structure.
   Answer: C
5. An aphid pierces its proboscis into the ———- to get plant juices. [ ]
   A) Xylem
   B) Phloem
   C) Cambium
   D) Vascular bundle
   Answer: B

10th Class Biology 3rd Lesson Transportation – The Circulatory System InText Questions and Answers

10th Class Biology Textbook Page No. 57

Question 1.
Answer the following after reading the experiment conducted by William Harvey.

1. In which blood vessels valves are found? What do you think is the function of the valves in them?
   Answer:
   Valves are present in the veins. If the blood moves in one direction, the valves fold towards the walls of the vessel, so that the blood can pass without trouble. If the blood moves in the opposite direction, the valves close.
2. Why do subcutaneous blood vessels bulge on the side away from the heart when the hand is tied?
   Answer:
   When the hand is tied the blood which is passing away from heart is stopped. So the subcutaneous blood vessels bulge.
3. The deep seated blood vessels (the arteries) bulge on the side towards the heart when tied. What do you understand from it?
   Answer:
   The blood which is passing towards the heart is stopped so the blood accumulates in the blood vessels and they bulge.
4. There are valves in the heart between atria and ventricles. Is the purpose of valves in the veins and arteries same ?
   Answer:
   The valves between each atrium and its ventricles are one way valves. They allow the blood to flow from the atrium to the ventricle without any hindrance.
   The purpose is same, back flow of blood is stopped.
5. Arteries are deeply seated in the body? Whereas veins are superficial why?
   Answer:
   1. Arteries are deep seated to prevent them from any damage. As arteries carry oxygenated blood, a damage to them results in loss of the oxygenated blood.
   2. Arteries lie deeper in the body because it helps them to contain high pressure so that they can carry blood from the heart to all the body parts.
   3. Because the deeper the arteries are in the body, the warmer the blood is. The warmer the blood, the more oxygen the haemoglobin is able to carry.
   4. Veins are located superficially as the pressure inside them is very low and contain deoxygenated blood.
      Also their superficial location helps in efficient flow of blood in them by muscular contraction and relaxation in our body.

Question 2.
After reading the experiments by Harvey fill in the following table. Use the clues/ options given in the first column.
Answer:

Structure / Function	Artery	Vein
1. Thickness of walls (thick / thin)	Thick	Thin
2. Valves (present / absent)	Absent	Present
3. Capacity to retain shape when blood is absent (can retain / collapse)	Can retain	Can not retain
4. Direction of blood flow (heart to organs / body organs to heart)	Heart to organs	Body organs to heart
5. Pressure in the vessel (low / high)	High	Low
6. Type of blood transported (oxygenated / de-oxygenated)	Oxygenated (except pulmonary artery)	De-oxygenated (except pulmonary veins)
7. Type of blood carried by pulmonary artery (de-oxygenated / oxygenated)	Deoxygenated	–

Question 3.
How many times did your pointer touch body parts in fig – 11(a) and (b)?
Answer:
One time.

Question 4.
How many times did your pointer touch the heart in fig – 11(a) and (b)?
Answer:
a) One time
b) Two times

Question 5.
How many times did the pointer touch respiratory organs in fig – 11(a) and (b)?
Answer:
One time.

Question 6.
Why do our legs swell?
Answer:
After overnight journey, in sitting position without moving, we feel that our feet (the lower part of the legs) swollen. This is called edema.
Because the blood circulation becomes slow in the lower portion and causes swelling.

10th Class Biology Textbook Page No. 64

Question 7.
Is there anything like that in plants which corresponds to circulatory system?
Answer:
Yes.
Vascular bundles are present in the plant parts which have xylem and phloem. These are responsible for the transportation of materials in plats.
Xylem transports water from roots to the leaves. Phloem transports food prepared by leaves to all the parts of the plant.

Question 8.
What is the mechanism behind this?
Answer:
Root absorb water due to Root Pressure and transpiration.

Question 9.
Are roots directly in contact with water?
Answer:
Yes. The root hairs are directly contact with water.

Question 10.
How is water absorbed?
Answer:
Water is absorbed due to Osmosis.

10th Class Biology Textbook Page No. 66

Question 11.
Is there any increase in the water level?
Answer:
Yes. There is an increase in the water level.

Question 12.
What is the role of xylem?
Answer:
Water absorbed by roots is transported to all the parts of the plant by Xylem

Think and Discuss

10th Class Biology Textbook Page No. 58

Question 1.
Artery walls are very strong and elastic. Why?
Answer:

1. When the blood enters with a pressure into arteries the walls will stretch.
2. This enables the arteries to withstand the increase in the pressure, without bursting. So the walls of the arteries are very strong and elastic.

Question 2.
Why do we compare arteries like tree which divides into smaller and smaller branches?
Answer:

1. Arteries carry oxygenated blood to the tissues.
2. The largest aorta after comes outside of the heart, it divides into small branches called arteries.
3. These arteries still divide into small arterioles and supply oxygenated blood to the tissues which are present throughout the body.
4. It looks like a tree with smaller and smaller branches. So we compare arteries like tree.

Question 3.
The lumen size is bigger in vein when compared with artery. Why?
Answer:

1. Veins are generally large in diameter, carry more blood volume.
2. Arteries are general small in diameter when compared with veins.
3. The walls of veins are more thick when compared with the walls of arteries.
4. So the lumen’s bigger in vein when compared with artery.

10th Class Biology 3rd Lesson Transportation – The Circulatory System Activities

Activity – 1

How can you find your pulse rate?
Answer:
1) Keep your index and middle fingers on your wrist below the thumb as shown in the figure.
2) You feel something pushing your fingers rhythmically up and down.
3) Count the rhythm also called pulse rate per minute.
4) Now stand up and jog for one minute standing at the same place. Note the pulse for a minute.

Name of the person	Pulse rate per minute
	at rest	after jogging
Naganeeraj	72	80
Nagamani	70	81
Chandra Sekhar	71	79
Shabnum	74	84
Mani	72	83

a) What did you observe? Is the pulse rate same in both conditions?
Answer:
No the pulse rate is not same in both condition. There is increase in pulse rate after jogging for one minute.

Activity – 2

Now observe the pulse rate of students of your class.
Try to observe your pulse rhythm in other ways such as climbing stairs, running etc. Take your shirt button and insert a matchstick and place it on your wrist.

1. What did you find?
   Answer:
   We find the button placed on the wrist moves up and down rhythmically
2. When do you think that our pulse rate goes up?
   Answer:
   The pulse rate goes up, when we climb up stairs or run, etc.
3. What does the pulse rate show?
   Answer:
   There is a relationship between the pulse rate and the heart beat. The pulse rate shows the heart beat.

Activity – 3

How do you measure the Heart beat and pulse rate at rest?
Answer:

1. I will make a paper tube 10 inch long and one inch in diameter.
2. Keep one end of it on the chest of a friend on a point in the centre around 6 inches below from his or her neck.
3. I keep my ear at the other end.
4. Listen carefully and count the beats for a minute.
5. Also find my friend’s pulse rate. Then 1 will note down my observations at least 10 students of my class in the following.
   

   Name of the student	Heart beat at rest/minute	Pulse rate at rest/minute
   Eswar	72	72
   Venkateswar Rao	70	70
   Gopinath	69	69
   Yashwanth	71	71
   Srinivas	72	72
   Manasa	68	68
   Kamala	70	70
   Lakshmi	71	71
   Kavitha	69	69
   Latha	70	70

6. Observation: It is found that the heart beat and the pulse rate are same in every movement.
   Prepare histogram between persons and heart beat and pulse rate at rest as shown in the sample graph. Here (a) bar indicates heart beat,
   (b) bar indicates pulse rate.
   X-axis: Name of the student Y-axis: Heart beat, pulse rate per minute.
   

Activity – 4

Aim: Observation of the internal structure of the mammalian heart.
Material required: Since the structure of all the mammalian hearts is similar, we take the sheep’s or goat’s heart for our observation. For this, we need the following materials.
Material required: Freshly collected specimen of heart of sheep/goat from the butcher, soda straw, sharp and long blade/ scalpel, tray and a jug of water, dissection scissors and forceps.
Procedure: Before coming to the class wash the heart thoroughly so that, blood is completely drained from the chambers of heart.
Take the soda straws and insert them into the stumps of the blood vessels.
Note your observations as you proceed.

1. How many layers are covering the heart?
   Answer:
   Two thin, transparent layers are covering the heart.
2. What is the shape of the heart?
   Answer:
   Heart is a pear shaped structure, triangle in outline, wider at the anterior end and narrower at the posterior end.
3. How many large blood vessel stumps are attached to the heart?
   Answer:
   There are five large blood vessels attached to the heart.
4. Which end of the heart is broader and which end is narrow?
   Answer:
   The anterior end of the heart is broader and the posterior end is narrow.
   Observe the internal structure – observe the wall of the heart.
5. Is the thickness of the wall of the heart uniform throughout?
   Answer:
   No, the thickness of the wall of the heart is not uniform throughout. Atria are thin and ventricles are thick.
6. How many chambers are there in the heart?
   Answer:
   There are four chambers in the heart. They are right atrium, left atrium, left ventricle and right ventricle.
7. Are all the chambers of the same size?
   Answer:
   All the chambers of the heart are not of the same size. Left atrium and ventricle are smaller when compared to that of right atrium and ventricle.
8. What other differences could you observe between the chambers?
   Answer:
   Left auricle and ventricle are smaller than right auricle and right ventricle.
9. Do you find any specific observation in between two chambers?
   Answer:
   Yes, I can find some specific observation in between two chambers.
10. Are all the chambers connected to each other?
    Answer:
    No, only atria and ventricles are connected to each other.
11. How are they connected to each other ? How are they separated?
    Answer:
    Auricles are connected to ventricles by valves and are separated by septae (septum).
12. How many blood vessels are attached to the heart?
    Answer:
    Five blood vessels are attached to the heart.
    They are
    1. Aorta,
    2. Pulmonary artery,
    3. Pulmonary vein,
    4. Superior venacava,
    5. Inferior venacava.
13. Are all the blood vessels rigid? How many of them are rigid?
    Answer:
    The rigid blood vessels are called arteries. They are
    1. The largest artery Aorta
    2. Pulmonary artery – which carries deoxygenated blood from heart to lungs.
14. Do you think that the stiffness / rigidity of blood vessel is something to do with circulation?
    Answer:
    The walls of the arteries are stiff/rigid. They are made up of muscle fibre and are elastic. When heart pumps blood into the arteries, the blood enters with a pressure into the arteries. Their walls will stretch and this enables the arteries to withstand the increase in the pressure without bursting.

Activity – 5

Write your observation of blood flow in arteries and veins.
Answer:
a) Aim: Observation of blood flow in arteries and veins.
Procedure:

1. Sit on a table with one leg dangling and the other resting on it so that the back of one knee rests on the knee of the other.
2. After some time we feel the leg which is on top give a series of small movements with each heart beat.
3. Repeat it for a long time.

Observation: The blood flow reduces to the leg and so develop “pins and needles”.
Conclusion: The blood flow from arteries to legs slowed down results pins and needles.

b) Swing the arm round several times to fill the veins with blood, hold the arm vertically downwards and gently press your finger along a prominent vein – stroking it in the reverse direction to the blood flow.
Observation: We can see the swellings.
Conclusion: Veins have to carry blood from body parts to the heart. When the arm is hold tightly blood is stopped in the veins there forms swelling.

Activity – 6

How is water absorbed? Explain with an experiment.
Answer:
Aim: To show that water is absorbed by the root hairs.
Required material : Mustard seedlings, filter paper slide and cover slip, a drop of water, microscope, hand lens.
Procedure: We need to germinate some mustard seeds. Examine some mustard seeds which have been grown on wet filter paper. Observe the mass of fine threads coming from the root by using hand lens. These are root hairs through which water enters the plant.
Gently squash a portion of the root hair between the slide and cover slip in a drop of water and examine under a microscope.
Note the thinness of the walls of the root hairs. The water enters the root hairs and passes inwards from cell to cell until it gets into the xylem vessels. Osmosis plays an important role in this.
Observation: It is observed that water is present in the xylem vessels.
Conclusion: The root hairs absorbs water with mineral salts into the transport tissue called xylem vessels by the process of osmosis.

Activity – 7

What is root pressure? Explain with an experiment.
Answer:
Aim: To demonstrate root pressure in plants.
Apparatus : Potted plant with stem cut, rubber tube, glass tube, clamp.
Procedure:

1. Take a regularly watered potted plant and cut the stem portion 1 cm above the ground level.
   
2. Then connect a glass tube by means of a strong rubber tubing as shown in the figure.
3. The size of glass tube should be equal to the size of the stem.
4. Take care while joining tube and stem being bound tightly, water cannot escape from the tube.
5. Now pour some water in the glass tube until water level can be seen above the rubber tube.
6. Mark the level of water (M₁) in tube.
7. Keep your arrangement aside for 2 to 3 hours.
8. Then observe and mark the water level (M₂) in the tube.

Observation: There is increase in the level.
Result: The raise in the water level is due to the root pressure created in the plant.

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:

Inspiration	Expiration
1. It is also called inhalation.	1. It is also called exhalation.
2. The air or water is taken into the respiratory organ.	2. The air or water is sent out of the respiratory organ.
3. It is an active process.	3. It is a passive process.
4. Rib cage moves forward and outward.	4. Rib cage moves downward and inward.
5. Diaphragm contracts and becomes flattened.	5. Diaphragm relaxes and becomes original dome shaped.
6. Increase in volume of thoracic cavity.	6. Decrease in volume of thoracic cavity.
7. Air pressure in lungs is less than the atmospheric pressure.	7. Air pressure in lungs is greater than the atmospheric pressure.

(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:

Respiration	Combustion
1. It occurs in living cells.	1. It is non – cellular.
2. Oxidation of food materials especially glucose to carbon dioxide and water is called respiration.	2. When sugar burns CO2 and water are produced and energy is released as heat. This process is called combustion.
3. Oxidation of sugar molecules occurs at the body temperature of an organism.	3. Heat is to be supplied for the sugar molecule to burn.
4. The energy is released in several stages.	4. The energy is released at once as heat.
5. Several intermediate substances are formed.	5. No intermediate substances are formed.
6. Enzymes are required for oxidation.	6. Enzymes are not required for combustion.
7. Respiration occurs in the presence of water.	7. Combustion occurs in the absence of water.
8. It is a controlled process.	8. It is an uncontrolled process.
9. Energy is stored in ATP in the body.	9. Energy is not stored and is released into the atmosphere.

(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 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

Improve your learning

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

Autotrophic nutrition	Heterotrophic nutrition
1. Organism makes its own food.	1. Organism can not makes its own food.
2. Food is prepared from C02, water and sunlight.	2) Food is prepared from other organism.
3. Chlorophyll is required.	3. Chlorophyll is not required.
4. It takes place during day time.	4. It takes place throughout the day.
5. Examples are all green plants and photosynthetic bacteria.	5. All animals, Fungi and some bacteria.

(b) Ingestion – Digestion :
Answer:

Ingestion	Digestion
1. Taking in of food into the body through mouth is called ingestion.	1. Breaking up of complex molecules of food into simple and small molecules is called digestion.
2. Ingestion does not change the chemical and mechanical structure of food.	2. Digestion changes the chemical and mechanical structure of food.

(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:

Light reaction	Dark reaction
1. It occurs in the grana of the chloroplast.	1. It occurs in the stroma of the chloroplast.
2. It occurs only in the presence of light.	2. It occurs in the presence or absence of light.
3. It occurs in the grana of the chloroplast.	3. It occurs in the stroma of the chloroplast.
4. Light reaction absorbs oxygen and light energy.	4. Dark reaction absorbs only CO2
5. End products are O2, ATP and NADPH.	5. End product is Glucose.
6. Photolysis of water occurs.	6. Carbon fixation occurs.
7. First stage of photosynthesis.	7. Second stage o: photosynthesis.

(d) Chlorophyll – Chloroplast:
Answer:

Chlorophyll	Chloroplast
1. Chlorophyll is the green coloured pigment present in the chloroplast.	1. It is the green coloured plastid enclosed by membranes.
2. It contains one atom of magnesium.	2. It consists of 3 membranes.
3. It harvests solar energy and convert into chemical energy.	3. It is responsible for enzymatic reactions leading to the synthesis of glucose.

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:

Raw materials	Sources
External factors: 1. Carbondioxide	Atmosphere
2. Sunlight	Sun
Internal factors: 3. Water	Ground water
4. Chlorophyll and enzymes	Present in leaf.

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.