Category: Class 8

Students can go through AP Board 8th Class Maths Notes Chapter 8 Exploring Geometrical Figures to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 8 Exploring Geometrical Figures

→ Shapes are said to be congruent if they have same shape and size.

→ Shapes are said to be similar if they have same shapes but in different size.

→ If we flip, slide or turn the congruent/similar shapes their congruence/similarity remain the same.

→ Some figures may have more than one line of symmetry.

→ Symmetry is of three types namely line symmetry, rotational symmetry and point symmetry.

→ With rotational symmetry, the figure is rotated around a central point so that it appears two or more times same as original.

→ The number of times for which it appears the same is called the order.

→ The method of drawing enlarged or reduced similar figures is called Dialation.

→ The patterns formed by repeating figures to fill a plane without gaps or overlaps are called tessellations.

→ Flip: Flip is a transformation in which a plane figure is reflected across a line, creating a mirror image of the original figure.

→ After a figure is flipped or reflected, the distance between the line of reflection and each point on the original figure is the same as the distance between the line of reflection and the corresponding point on the mirror image.

→ Rotation: “Rotation “means turning around a center.
The distance from the center to any point on the shape stays the same. Every point makes a circle around the center.

There is a central point that stays fixed and everything else moves around that point in a circle.
A “Full Rotation” is 360°.

→ Now observe the following geometrical figures.

In all the cases if the first figure in the row is moved, rotated and flipped do you find any change in size and shape? No, the figures in every row are congruent they represent the same figure but oriented differently.

→ If two shapes are congruent, still they remain congruent if they are moved or rotated. The shapes would also remain congruent if we reflect the shapes by producing their mirror images.

→ We use the symbol ≅ to represent congruency.

Students can go through AP Board 8th Class Maths Notes Chapter 7 Frequency Distribution Tables and Graphs to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 7 Frequency Distribution Tables and Graphs

→ The Central Tendencies are 3 types. They are

1. Arithmetic Mean
2. Median
3. Mode

→ Information, available in the numerical form or verbal form or graphical form that helps in taking decisions or drawing conclusions is called Data.

→ Arithmetic mean of the ungrouped data = (short representation) where ∑x_i represents the sum of all x_is, where ‘i’ takes the values from 1 to n.

→ Arithmetic mean = Estimated mean + Average of deviations

→ Mean is used in the analysis of numerical data represented by unique value.

→ Median represents the middle value of the distribution arranged in order.

→ The median is used to analyse the numerical data, particularly useful when there are a few observations that are unlike mean, it is not affected by extreme values.

→ Mode is used to analyse both numerical and verbal data.

→ Mode is the most frequent observation of the given data. There may be more than one mode for the given data.

→ Representation of classified distinct observations of the data with frequencies is called ‘Frequency Distribution’ or ‘Distribution Table’.

→ Difference between upper and lower boundaries of a class is called length of the class denoted by ‘C’.

→ In a class the initial value and end value of each class is called the lower limit and upper limit respectively of that class.

→ The average of upper limit of a class and lower limit of successive class is called upper boundary of that class.

→ The average of the lower limit of a class and upper limit of preceding class is called the lower boundary of the class.
The progressive total of frequencies from the last class of the table to the lower boundary of particular class is called Greater than Cumulative Frequency (G.C.F).

→ The progressive total of frequencies from first class to the upper boundary of particular class is called Less than Cumulative Frequency (L.C.F.).

→ Histogram is a graphical representation of frequency distribution of exclusive class intervals. When the class intervals in a grouped frequency distribution are varying we need to construct rectangles in histogram on the basis of frequency density.
Frequency density = \(\frac{\text { Frequency of class }}{\text { Length of that class }}\) × Least class length in the data

→ Frequency polygon is a graphical representation of a frequency distribution (discrete/ continuous).

→ Infrequency polygon or frequency curve, class marks or mid values of the classes are taken on X-axis and the corresponding frequencies on the Y-axis.

→ Area of frequency polygon and histogram drawn for the same data are equal.

→ A graph representing the cumulative frequencies of a grouped frequency distribution against the corresponding lower/upper boundaries of respective class intervals is called Cumulative Frequency Curve or “Ogive Curve”.

Students can go through AP Board 8th Class Maths Notes Chapter 6 Square Roots and Cube Roots to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 6 Square Roots and Cube Roots

→ The product of two same numbers is called its square.
Ex: 1) x × x = x²
2) 6 × 6 = 6² = 36

→ The digits in the units place of a square number are 0, 1, 4, 5, 6, 9.

→ If the digits 2,3, 7 or 8 are in the units place of an umber then it is not a perfect square.

→ If there are ‘n’ digits in a number then the no.of digits in its square = 2n or (2n -1).

→ Sum of ‘n ‘ consecutive odd numbers = n²

→ The square of any odd number say ‘n’ can be expressed as the sum of two consecutive numbers as

→ If a, b, c are any three positive integers and a² + b² = c² then a, b, c are called Pythagorean triplets. Ex: (3, 4, 5) (5, 12, 13).

→ If a square number is expressed, as the product of two equal factors, then one of the factors is called the square root of that square number. Thus, the square root of 169 is 13. It can be expressed as √169 = 13 (symbol used for square root is √). Thus it is the inverse operation of squaring.

→ If the same number is multiplied itself by 3 times then it is called a cube of a number. Ex: cube of x = x × x × x = x³

→ If a cube number is expressed, as the product of 3 equal factors, then one of he factors is called the cube root of that number.
Symbol for cube root is \(\sqrt[3]{ }\)
Ex: \(\sqrt[3]{64}=\left(4^{3}\right)^{1 / 3}\) = 4

→

Students can go through AP Board 8th Class Maths Notes Chapter 5 Comparing Quantities Using Proportion to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 5 Comparing Quantities Using Proportion

→ Two simple ratios are expressed like a single ratio as the ratio of product of antecedents to product of consequents and we call it compound ratio of the given two simple ratios.
a : b and c : d are any two ratios, then their compound ratio is \(\frac{a}{b}\) × \(\frac{c}{d}\) = \(\frac{ac}{bd}\) i.e. ac : bd.

→ A percentage(%) compares a number to 100. The word percent means “per every hundred” or “out of every hundred”. 100% = \(\frac{100}{100}\) it is also a fraction with denominator 100.

→ Discount is a decrease percent of marked price. Price reduction is called rebate or discount. It is calculated on marked price or list price.

→ Profit or loss is always calculated on cost price. Profit is an example of increase percent of cost price and loss is an example of decrease percent of cost price.

→ VAT will be charged on the selling price of an item and will be included in the bill.
VAT is an increase percent on selling price.

→ Simple interest is an increase percent on the principal.

→ Simple interest (I) = \(\frac{P \times T \times R}{100}\)
where P = Principal, T = Time inyears, R = Rate of interest.

→ Amount = Principal + Interest = P + \(\frac{P \times T \times R}{100}\) = P\(\left(1+\frac{T \times R}{100}\right)\)

→ Compound interest allows you to earn interest on interest.

→ Amount at the end of ‘n’ years using compound interest is A = P \(\left(1+\frac{R}{100}\right)^{n}\)

→ The time period after which interest is added to principal is called conversion period.
When interest is compounded halfyearly, there are two conversion periods in a year, each after 6 months. In such a case, ha If year rate will be half of the annual rate.

→ Note: 1.615 : 1 is called as golden ratio.
In ancient Greece, artists and architects believed there was a particular rectangular shape that looked very pleasing to the eye. For rectangles of this shape, the ratio of long side to the short side is roughly 1.615 : 1. This ratio is very close to what is known as golden ratio.

Students can go through AP Board 8th Class Maths Notes Chapter 4 Exponents and Powers to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 4 Exponents and Powers

Laws of Exponents:

→ a × a × a …… m times = a^m

In a^m, a is called base; m is called exponent/ power.

→ a^m × aⁿ = a^m+n

→ \(\frac{\mathrm{a}^{\mathrm{m}}}{\mathrm{a}^{\mathrm{n}}}\) = a^m-n (m > n)
⇒ \(\frac{1}{a^{n-m}}\) (m < n)

→ (ab)^m = a^m . b^m

→ a⁰ = 1

→ a^-n = \(\frac{1}{a^{n}}\)

→ aⁿ = \(\frac{1}{a^{-n}}\)

→ \(\left(\frac{a}{b}\right)^{m}\) = \(\frac{a^{m}}{b^{m}}\)

→ \(\left(a^{m}\right)^{n}\) = a^mn

→

→ \(\sqrt[n]{a}\) = \((\mathrm{a})^{1 / \mathrm{n}}\)

Students can go through AP Board 8th Class Maths Notes Chapter 3 Construction of Quadrilaterals to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 3 Construction of Quadrilaterals

→ A closed four sided polygon is called a quadrilateral.

→ A quadrilateral has 4 sides, 4 vertices, 4 angles and 2 diagonals.

→ The sum of the 4 angles of a quadrilateral is 360°.

Type of a quadrilateral	No. of individual measurements
1. Quadrilateral	5
2. Trapezium	4
3. Parallelogram	3
4. Rectangle	3
5. Rhombus	2
6. Square	1

→ Quadrilateral and their types:

→ Five independent measurements are required to draw a unique quadrilateral.

→ A quadrilateral can be constructed uniquely, if
a) The lengths of four sides and one angle are given
b) The lengths of four sides and one diagonal are given
c) The lengths of three sides and two diagonals are given
d) The lengths of two adjacent sides and three angles are given
e) The lengths of three sides and two included angles are given

→ The two special quadrilaterals, namely rhombus and square can be constructed when two diagonals are given.

Students can go through AP Board 8th Class Maths Notes Chapter 2 Linear Equations in One Variable to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 2 Linear Equations in One Variable

→ An algebraic equation is equality of algebraic expressions involving variables and constants.

→ If the degree of an equation is one then it is called a linear equation.

→ If a linear equation has only one variable then it is called a linear equation in one variable or simple equation. ‘

→ The value which when substituted for the variable in the given equation makes L.H.S. = R.H.S. is called a solution or root of the given equation.

→ Just as numbers, variables can also be transposed from one side of the equation to the other side.
Note: When we transpose terms
‘+’ quantity becomes ’-‘ quantity,
‘-‘ quantity becomes ‘+’ quantity.
‘×’ quantity becomes ‘÷’ quantity.
‘÷’ quantity becomes ‘×’ quantity.
Also
Also,
(+) × (+) = +
(+) × (-) = –
(-) × (+) = –
(-) × (-) = +

Students can go through AP Board 8th Class Maths Notes Chapter 1 Rational Numbers to understand and remember the concepts easily.

AP State Board Syllabus 8th Class Maths Notes Chapter 1 Rational Numbers

→ The numbers which are expressed in the form of \(\frac{p}{q}\) where p and q are integers and q ≠ 0, are called “Rational Numbers” which are denoted by the letter ‘Q’.

→ Rational numbers are closed under the operations of addition, subtraction and multiplication.

→ Rational numbers are not closed on division.

→ Whole numbers:

→ Whole numbers:

→ The additive inverse of a is – a. (∵ a + (-a) = 0)

→ The multiplicative inverse of a is \(\frac{1}{a}\). (∵ a × \(\frac{1}{a}\) = 1)

→ The operations addition and multiplications are

1. Commutative for rational numbers.
2. Associative for rational numbers.

→ ‘0’ is the additive identity for rational number.

→ ‘1’ is the multiplicative identity for rational number.

→ A rational number and its additive inverse are opposite in their sign.

→ The multiplicative inverse of a rational number is its reciprocal.

→ Distributivity of rational numbers a, b and c is a(b + c) = ab + ac and a(b – c) = ab – ac.

→ Rational numbers can be represented on a number line.

→ There are infinite number of rational numbers between any two given rational numbers.

→ The concept of mean help us to find rational numbers between any two rational numbers.

→ The decimal representation of rational numbers is either in the form of terminating decimal or non-terminating recurring decimals.

AP State Syllabus AP Board 8th Class Biology Important Questions Chapter 11 Why Do We Fall Ill

AP State Syllabus 8th Class Biology Important Questions 10th Lesson Why Do We Fall Ill

8th Class Biology 10th Lesson Why Do We Fall Ill 1 Mark Important Questions and Answers

Question 1.
What is health?
Answer:
Health is a state of physical, mental and social well – being.

Question 2.
On what factors the health of an individual depends?
Answer:
The health of an individual is dependent on his or her physical surroundings and his / her economic status.

Question 3.
What is a disease ?
Answer:
Disease is actually self – explanatory. In other words, literally means being uncomfortable.

Question 4.
What is necessary for individual health ?
Answer:
Social equality and harmony are necessary for individual health.

Question 5.
What will happen if there is a disease ?
Answer:
When there is a disease, either the functioning or the appearance of one or more systems of the body will change for the worse.

Question 6.
What are acute diseases ?
Answer:
Some diseases last for only very short periods of time and these are called acute diseases.

Question 7.
What are chronic diseases ?
Answer:
Chronic diseases have very drastic, long – term effects on people’s health as compared to acute diseases.

Question 8.
What is the cause of a disease ?
Answer:
Lack of good nourishment may be the cause of a disease.

Question 9.
What are infectious diseases ?
Answer:
Diseases where microbes are the immediate causes are called infectious diseases.

Question 10.
Which bacteria is responsible for peptic ulcers ?
Answer:
Helicobacter pylori is responsible for peptic ulcers.

Question 11.
Name the organisms that cause diseases.
Answer:
Organisms that cause diseases are virus, bacteria, fungi, protozoans and worms.

Question 12.
Name the diseases caused by bacteria.
Answer:
Typhoid, cholera, tuberculosis and anthrax are caused by bacteria.

Question 13.
What diseases are caused by protozoans ?
Answer:
Protozoans cause malaria and kalaazar.

Question 14.
What are communicable diseases ?
Answer:
Diseases that spread from an infected person to other person by many microbial agents are called communicable diseases.

Question 15.
What is the function of our immune system ?
Answer:
In our body, the immune system fight and kill the disease causing organisms that enter into our body and defend us from diseases.

Question 16.
What are vectors ?
Answer:
Many diseases transmitted by other animals. These animals carry the infecting agents from a sick person to a healthy person. Such animals are called vectors. Ex: Mosquitoes.

Question 17.
Name the diseases caused by mosquitoes.
Answer:
Encephalitis or brain fever, filaria or elephantiasismalaria, dengue etc., are caused by mosquitoes.

Question 18.
Name the disease that causes physical contact.
Answer:
AIDS disease is caused by physical contact.

Question 19.
How do we kill microbes?
Answer:
By using antibacterial and anti – viral medicines we can kill microbes and also there are drugs that kill protozoa such as malarial parasite.

Question 20.
Why making anti – viral medicines is harder than making antibacterial medicines ?
Answer:
Because viruses have few biochemical mechanisms of their own.

Question 21.
What are infectious diseases?
Answer:
Diseases where microbes are the immediate causes are called infectious diseases.

Question 22.
What are symptoms?
Answer:
Some characteristic signs or indications that appear during sickness can help us to identify the sickness are called symptoms!

Question 23.
What is manifestation?
The appearance of the symptoms of a disease is called manifestation of the disease.

Question 24.
What is immunization?
Answer:
The creation of immunity usually against a particular disease, especially treatment by vaccination of an organism for the purpose of making it immune to a particular disease.

Question 25.
What are the different means by which infectious diseases are spread?
Answer:
Infectious diseases are spread through contaminated air, water, food and vectors like mosquitoes, flies, cockroaches, snails and even lies.

Question 26.
What are the vaccines available for preventing infectious diseases?
Answer:
There are vaccines against tetanus, diphtheria, whooping cough, measles, polio and many others.

Question 27.
Who discover vaccine for small pox for the first time?
Answer:
An English physician named Edward Jenner discovered vaccine forsmall pox for the first time.

Question 28.
Why are we normally advised to take bland and nourishing food when we are sick?
Answer:
When we fall sick our normal body functions will be affected and the digestion becomes slow, so it is advised to take bland and nourishing food.

Question 29.
What is needed to be healthy?
Answer:
Proper and sufficient nourishment and clean surroundings and food helps lis to be healthy.

Question 30.
Name the diseases that do not spread.
Answer:
Non – infectious diseases like cancer, high blood pressure do not spread.

8th Class Biology 10th Lesson Why Do We Fall Ill 2 Marks Important Questions and Answers

Question 1.
What are the diseases caused by bacteria in Man?
Answer:

1. Cholera
2. Typhoid
3. Diptheria
4. Whooping cough
5. Tetanus
6. Tuberculosis
7. Leprosy

Question 2.
Name the diseases caused by viruses in man.
Answer:

1. Small pox
2. Chicken pox
3. Measles
4. Mumps
5. Poliomelitis

Question 3.
What are the diseases caused by Protozoans in Man?
Answer:

1. Malaria
2. Kala Azar
3. Amoebic Desentry

8th Class Biology 10th Lesson Why Do We Fall Ill 4 Marks Important Questions and Answers

Question 1.
Draw the picture of SARS VIRUS in your scrap book and write the size of SARS VIRUS.
Answer:
Picture of SARS VIRUS

The size of SARS VIRUS is 500 nano metres, which is half a micrometre, which is one thousandth of a millimetre.

Question 2.
Draw the picture of staphylococci bacteria. In what way it affect the health of people?
Answer:
Staphylococci Bacteria

Staphylocoecci bacteria cause acne.

Question 3.
Draw a picture showing an adult round worm and answer the given questions:
a) What is the scientific name of round worm?
b) Where does it live in human beings?
Answer:
Round Worm

a) The Scientific name of Round Worm is Ascaris lumbricoides.
b) It stays in the small intestine of human beings.

Question 4.
Draw a picture showing the air borne diseases will spread in the air.
Answer:
Spread of air borne diseases

Question 5.
Draw a flow chart which shows common methods of transmission of diseases. How the animals transmit diseases? Explain.
Answer:

We lie in an environment that is full of many other creatures apart from us. It is inevitable that many diseases will be transmitted by other animals.
These animals carry the infecting agents from a sick person to another potential host. These animals are intermediates and are called vectors.
The commonest vectors are mosquitoes. The female mosquitoes need highly nutri¬tious food in the form of blood in order to be able to lay mature eggs. In this way they can transfer diseases from person to person.

Question 6.
How does death occurs in AIDS patients?
Answer:

1. In HIV infection, the virus goes to the immune system and damage its function.
2. The body can no longer fight off with even minor infections.
3. Even mild cold becomes Pneumonia. Thus ultimately these infections kill the people suffering from HIV – AIDS.

8th Class Biology 10th Lesson Why Do We Fall Ill Important Questions and Answers

Question 1.
Prepare a pamphlet to aware people to maintain a hygienic surrounding.
Answer:
Pamphlet
“Prevention is better than cure”. So, it is better for us to prevent diseases rather than treatment. You should keep our surroundings clean and hygienic wash your hands with soap or handwash lotion thoroughly before consuming food. Wash your hands with soap after defecation. You should consume your food only when it is hot. Do exercises daily to keep you fit and healthy. Try to cultivate good habits which keep you healthy always. Use mosquito nets to avoid mosquito bites.
“SWACH BHARAT – SWASTH BHARAT”.

AP State Syllabus AP Board 8th Class Biology Important Questions Chapter 10 Not For Drinking-Not For Breathing

AP State Syllabus 8th Class Biology Important Questions 10th Lesson Not For Drinking-Not For Breathing

8th Class Biology 10th Lesson Not For Drinking-Not For Breathing 1 Mark Important Questions and Answers

Question 1.
Which department issues the pollution under control certificate?
Answer:
The pollution check up centre issues the certificate.

Question 2.
For how much time is it valid?
Answer:
It is valid for six months.

Question 3.
For which types of vehicles has it been issued?
Answer:
All types of vehicles like motor bike, scooter, car, bus, lorry etc.

Question 4.
What is emission test?
Answer:
The test conducting of the gases releasing from the vehicle is called emission test.

Question 5.
What components are tested in the pollution check up centre?
Answer:
Carbon dioxide, carbon monoxide, nitrogen, hydrocarbons, sulphur dioxide etc.

Question 6.
What will happen if harmful microorganisms or substances enter your body? How do you feel?
Answer:
If harmful microorganism enter the body the normal functioning of the body will be disrupted or disturbed. We feel sick.

Question 7.
What is the effect of rapid increase in the number of vehicles?
Answer:
With the number of vehicles increase, the pollution also increases, which causes air pollution.

Question 8.
What is pollution?
Answer:
Anything that is harmful to the environment is called pollution.

Question 9.
When do all the living organisms with in the environment will be healthy and thriving?
Answer:
When everything is working the way it should be all the living organisms with the environment including humans are healthy and thriving.

Question 10.
Name the diseases caused by air pollution.
Answer:
Diseases of the respiratory system like lung cancer, Asthma etc.

Question 11.
What do our elders talk about the environment?
Answer:
Our elders talk about the blue sky, clean water and fresh air that was available in their times.

Question 12.
What is our environment made up of?
Answer:
The environment is made up of systems, cycles and specialized relationships between living and non – living elements.

Question 13.
Name some substances which impact the health of our earth.
Answer:
Litter, car exhaust, motor oil, used tires, smoke, chemicals, disposed computer, mobile phone material etc., all of these can have an instant or a gradual impact on the health of our earth.

Question 14.
What are the four major gases in the air?
Answer:
The four major gases are nitrogen, oxygen, argon and carbondioxide.

Question 15.
Which is the essential element for survival of all living organisms?
Answer:
The atmosphere contains 21 % of oxygen which is essential for survival of all living organisms.

Question 16.
How is carbon dioxide important?
Answer:
Carbon dioxide which is 0.033% is essential for the process of photosynthesis in plants.

Question 17.
What is air pollution?
Answer:
The contamination of air by impurities which may have harmful impacts on the living organisms and the non-living components of the environment is called air pollution.

Question 18.
What are pollutants?
Answer:
Pollutants are the substances which contaminate the environment.

Question 19.
Name the main pollutants in the atmosphere.
Answer:
Suspended particulate matter, carbondioxide, carbon monoxide, oxides of sulphur and nitrogen CFCs and heavy metals.

Question 20.
Name the natural disasters in the world.
Answer:
The natural disasters in the world are volcanic eruptions, forest fires and sand storms which leads to air pollution.

Question 21.
What is the problem with airborne pollutants?
Answer:
The problem with airborne – pollutants is the way winds criss – cross the globe, picking up pollutants and carrying them all over the world. Air pollution is not just a local concern.

Question 22.
What pollutants are released by forest fires?
Answer:
Forest fires release carbon particles (ash) into the air and pollute the air.

Question 23.
What gas is released from decay of organic matter?
Answer:
Decay of organic matter releases Ammonia gas into air.

Question 24.
What gas is released from decay of organic matter lying under water?
Answer:
Decay of organic matter lying under water releases Methane gas as air pollution.

Question 25.
How do pollen grains pollute the air?
Answer:
Pollen grains released by plants remain floating in the air and pollute it.

Question 26.
What gases are produced by burning fuels?
Answer:
Burning fuels pollute the air by producing carbon – monoxide, sulphur dioxide, smoke, soot and ash.

Question 27.
What gases are emitted by vehicles?
Answer:
Sulphur dioxide, nitrogen dioxide, carbon monoxide, unburnt hydrocarbons, lead compounds and soot.

Question 28.
Name the polluted areas and the factories present in that area.
Answer:

1. Prakasam district – Granite factory
2. Macharla – Cement factory
3. Piduguralla – Lime stone

Question 29.
Name various industries that pollute the air.
Answer:
Granite, lime, cement factories pollute the air by releasing sulphur dioxide, nitrous oxide, chlorine fly ash, dust, asbestos dust etc.

Question 30.
How local people are suffering living near Parawada and Krishnapatnam Thermal Power Plants?
Answer:
The Thermal power plants release fly ash, sulphur dioxide and radio active substances into air, water and land, local people are suffering from lung cancer and skin allergies.

Question 31.
What are the problems face by the people living near the granite factory?
Answer:
The people living near the granite factory are facing several health problems like respiratory bronchitis and asthma.

Question 32.
How are Nuclear power plants dangerous?
Answer:
The two problems of Nuclear power plants are radio active waste and melt downs.

Question 33.
What are melt downs?
Answer:
Melt downs are caused by too much heat in the power plant. During melt down the power plant makes more Radio active pollution.

Question 34.
How do power plants release power?
Answer:
Power plants produce power by using water, coal and gas.

Question 35.
How do Nuclear power plants produce power?
Answer:
By using Radio active elements like uranium.

Question 36.
How agriculture pollutes land and water?
Answer:
Use of fertilizers and pesticides in agriculture pollutes not only air but also land and water.

Question 37.
What is the result of deforestation?
Answer:
The destruction of forests and woods is called deforestation. It has resulted in the reduction of indigenous forests.

Question 38.
If forests reduce what would happen?
Answer:
If forests reduce the level of carbondioxide increases resulting to global warming.

Question 39.
In which devices chloro flouro carbons are used?
Answer:
Chloro flouro carbons (CFC) are used in refrigerators, Air Conditioners and aerosol sprays. CFC pollutes air by depleting the ozone layer.

Question 40.
How is mining cause pollution?
Answer:
Mining of coal and stone releases coal dust and stone dust that cause air pollution.

Question 41.
Why do the currently cars and buses not allowed to drive to the Taj Mahal?
Answer:
The motor vehicles and the Industries located in and around Agra for rubber processing, chemicals oil refinery of Mathura, iron foundries have been responsible for the colour change of Taj Mahal from white to yellow.

Question 42.
What did the Archeological department of lndia declared towards Taj Mahal?
Answer:
The Archeological department declared that 2\(\frac{1}{2}\) km around Taj Mahal is no drive zone.

Question 43.
What is the unforgettable tragedy of Bhopal?
Answer:
On second December 1984 about 3000 human beings died, about 5000 were paralized in just one night at Bhopal.

Question 44.
What is the reason for the tragedy at Bhopal?
Answer:
The reason for this is the leakage of Methyl isocynate into the air from an insecticide factory managed by union carbide.

Question 45.
What are the affects caused by air pollution?
Answer:
Air pollution causes certain diseases including shortness of breath, sore throat, chest pain, nausea, asthma, bronchitis and lung cancer.

Question 46.
How is like the air pollution?
Answer:
Air pollution is like a slow poison.

Question 47.
How to reduce air pollution from industries?
Answer:
Install electrostatic precipitators in the chimney of industries.

Question 48.
How to reduce pollution from vehicles?
Answer:
Reduce vehicular emission by using non-polluting fuels like CNG.

Question 49.
What is Vanamahotsav?
Answer:
We can protect plants and trees. On the day of Vanamahotsav lakhs of trees are planted in July every year.

Question 50.
Name one of the most polluted area in India.
Answer:
Patancheru, a suburban mandal in Medak district is a major industrial hub of the state is one of the most polluted area in India.

Question 51.
How are the villages badly affected by pollution?
Answer:
They are affected with some diseases like cancer, respiratory diseases and heart diseases by poisons in air, water and on land.

Question 52.
What is water pollution?
Answer:
The contamination of water with unwanted and harmful substances such as sewage, toxic chemicals, industrial waste etc., is called water pollution.

Question 53.
What is the character of normal water?
Answer:
Normal water is colourless without any smell or any unwanted substances. Water which is suitable for drinking is called potable water.

Question 54.
How Musi river got polluted?
Answer:
The people living near Musi throw large quantities of garbage, unwanted sewage, industrial waste, dead bodies, polythene bags, hot water and statues of deities and many other materials and made the river polluted.

Question 55.
What is definite source of pollution?
Answer:
Definite source of pollution is due to discharges from a single source, such as industrial site.

Question 56.
What is Biodegradable waste?
Answer:
Biodegradable waste consists of mainly human and animal waste.

Question 57.
How do plant nutrients pollute water?
Answer:
Phosphates sand nitrates – chemical fertilizers from agriculture run – off due to rain and industrial waste enter into water through sewage and pollute the water.

Question 58.
How is heat polluting water?
Answer:
As water, temperature increases, the amount of dissolved oxygen decreases. So thermal pollution often reduces the aquatic life diversity in water.

Question 59.
How is water polluted by sediment?
Answer:
Sediment pollution is formed by the sources such as constructional, agricultural, logging, flooding and city runoff.

Question 60.
What is Eutrophication?
Answer:
The enrichment of water by nutrients leading to excessive plant growth and duplication of oxygen is known as Eutrophication.

Question 61.
How is fluorine hazardous substance to ground water?
Answer:
Fluorine mixed in ground water cause dangerous disease called fluorosis.

Question 62.
What are 3R’s principles?
Answer:
The 3R’s principles are Reduce the usage of the materials, Reuse them for secondary purpose and Recycle the material again and again.

Question 63.
How should we maintain natural resources?
Answer:
We should keep the natural resources clean and healthy not only for us but also future generations.

8th Class Biology 10th Lesson Not For Drinking-Not For Breathing 2 Marks Important Questions and Answers

Question 1.
Complete this flow chart.

Answer:

1. Human activities
2. Volcanic eruptions
3. Forest fires
4. Sand cyclones
5. CFCs
6. Mining
7. Sewage
8. Industrial effluents
9. Toxic chemicals

Question 2.
Complete this flow chart.

Answer:
2) Industrial emissions
3) Atomic power plant radiation
4) Automobile exhausts
5) Fly ash

Question 3.
Heat can be a source of pollution ? How does it effect the aquatic life?
Answer:

1. As the water temperature increases, the amount of dissolved oxygen decreases.
2. Fish and plants require certain temperature and oxygen levels to survive.
3. So, thermal pollution often reduces the aquatic life diversity in the water.

8th Class Biology 10th Lesson Not For Drinking-Not For Breathing 4 Marks Important Questions and Answers

Question 1.
“It is much better to worship Ganesh Idol made of clay than Idol of Plaster of Paris” – said Kavitha. How do you support her ? How do you appreciate her attitude?
Answer:

1. I appreciate Kavitha’s attitude towards pollution free society.
2. ‘Plaster of Paris’ idol consists of different harmful chemicals. During “Nimajjanam” these are immersed in different water bodies which leads to water pollution.
3. Worshipping idols made with clay is eco-friendly.
4. Hence, I appreciate her environmental concern and eco-friendly nature.

Question 2.
Prepare some slogans which create awareness among people on air pollution.
Answer:

1. Stop pollution – Save life
2. Polluting water – Ending our lives
3. Save the nature – Nature will save you
4. Live and let live.
5. Nature is for humans need – Not for his greed.
6. Solar energy – Forever energy

Question 3.
What are the industries that cause water pollution?
Answer:

1. Textile industries
2. Chemical industries
3. Leather industries
4. Pesticide industries
5. Paint factories
6. Fertilizer industries – are causing water pollution.

8th Class Biology 10th Lesson Not For Drinking-Not For Breathing Important Questions and Answers

Question 1.
Natural resources are the divine gift for us by nature. We can use these resources in a meaningful way which helps us. If we destroy these resources human life will become an unsolvable puzzle. We should keep these resources clean and healthy not only for us but also for future generation.
Read the above paragraph and answer the questions given below.
a) How should we use our natural resources?
b) What would happen if we use natural resources injudiciously?
Answer:
a) We should use the natural resources discriminately. They are the gifts of nature. For example we should minimise the usage of fossil fuels and encourage the usage of alternative energy sources like solar energy and wind energy. We should use CNG in place of diesel and petrol in vehicles to restore fossil fuels for longer periods.
b) Man’s life on earth turns into a mysterious puzzle. Life is not possible for us.

Question 2.
Observe the above diagram and answer the following questions:

1. What does the diagram represent?
2. Which gas is more in quantity in the given picture?
3. What will happen if the percentage of carbon dioxide will increase in the atmosphere?
4. When can you say that carbon dioxide is not a pollutant?

Answer:

1. The above diagram tell us about the percentage of different gases present in our atmosphere.
2. Nitrogen.
3. The increase in CO₂ levels results in the increasing temperatures on the earth. As a result the glaciers in the polar region melt and rise in sea levels occur. It leads to submergence of many cities of the shore.
4. If CO₂ levels are below 0.03%, then it is considered as non – pollutant.

Question 3.
Read the following passage and answer the questions.
Here are two main sources of water pollution; definite sources and non-definite sources. Definite source pollution is due to discharges from a single source, such as an industrial site. It includes factories, waste water treatment facilities, septic systems, and other sources that are clearly discharging pollutants into water sources. Non definite-source pollution involves many small sources that combine to cause significant pollution. For instance, the movement of rain or irrigation water over land picks up pollutants such as fertilizers, herbicides and insecticides carries them into rivers, lakes, reservoirs, coastal waters, or groundwater. Non-definite sources are more difficult to identify, as they cannot be traced back to a particular location. Landfills can also be a non-definite source of pollution, if substances leach from the landfill into water supplies.
a) Which sources of water pollution are difficult to identify?
b) What are definite sources of water pollution? Give two examples.
Answer:
a) Non-definite
b) Definite source pollution is due to discharge from a single source such as an industrial site. Examples are factories, waste water treatment plants etc.

AP State Syllabus AP Board 8th Class Biology Important Questions Chapter 9 Production and Management of Food From Animals

AP State Syllabus 8th Class Biology Important Questions 9th Lesson Production and Management of Food From Animals

8th Class Biology 9th Lesson Production and Management of Food From Animals 1 Mark Important Questions and Answers

Question 1.
From where do we obtain food?
Answer:
We obtain food from plants and animals.

Question 2.
What are the food items that are obtained from animals?
Answer:
We obtain milk, meat and eggs from animals.

Question 3.
What is animal husbandry?
Answer:
Providing food, shelter, protection and breeding of animals is called animal husbandry.

Question 4.
How did man use animals since long time?
Answer:
Since long time, man used animals not only for obtaining food but also for agriculture, transportation etc.

Question 5.
Why did early man domesticate only some of the animals?
Answer:
The early man domesticated only some of the animals which provide him food, clothing and the animals which are helpful for agriculture and transportation.

Question 6.
In what way the animals are useful to us?
Answer:
Buffalo and cow give us milk, hens give us eggs and meat, goats and sheep provide us meat, ox, bulls, donkeys are useful for agriculture and transportation.

Question 7.
What do farmers believe in our country?
Answer:
In our country farmers believe that animal husbandry is part and parcel of agriculture.

Question 8.
Name the animals that domesticate by the people living in rural areas.
Answer:
People living in rural areas domesticate animals like cows, buffaloes, bullocks, goats, sheep, pigs, hens, etc.

Question 9.
What is the important issue in Animal husbandry?
Answer:
Supplying of nutritious food, accommodating clear and hygienic shelters for animals is important issue in animal husbandry.

Question 10.
Where do people rear their cattle in the village?
Answer:
Generally villagers send their cattle to rear at the places where grass is easily available.

Question 11.
Where do farmers keep their cattle?
Answer:
Farmers keep their cattle in the sheds.

Question 12.
Name the agricultural practices done by using bullocks and he-buffaloes.
Answer:
Ploughing and levelling the field farmers use bullocks and he-buffaloes.

Question 13.
How do cattle rearers protect their cattle?
Answer:
Cattle rearers make fences in the fields at off crop seasons.

Question 14.
How is the milk production effected?
Answer:
Milk production is effected by viral and bacterial diseases.

Question 15.
In rainy season how are cattle protected from mosquitoes?
Answer:
Cattle can be protected by covering mosquito nets.

Question 16.
Who will provide treatment and health care for cattle?
Answer:
Veterinary doctor will provide treatment and health care for cattle.

Question 17.
Name the dangerous disease in cows and buffaloes.
Answer:
Galikuntu is a common and dangerous disease in cows and buffaloes.

Question 18.
From which disease sheep and goats will suffer?
Answer:
Sheep and goats will suffer from worm infections (Nattala Vyadhi)

Question 19.
How do our government treats milk production?
Answer:
Our Government treats milk production as an industry.

Question 20.
How much milk is given by traditional species of cows?
Answer:
2 to 5 litres of milk per day.

Question 21.
How much milk is given by murra species?
Answer:
Murra species give up to 8 litres of milk per day.

Question 22.
Name the traditional varieties of cows.
Answer:
Haryana, Jaferabad, Nagapuri are the traditional varieties which give good quantity of milk.

Question 23.
Name the foreign varieties of cows.
Answer:
Jersy (England) and Holstein (Denmark).

Question 24.
What is the milk yield from foreign varieties?
Answer:
They give 8 to 20 litres of milk.

Question 25.
What is pasteurization?
Answer:
The destruction of disease producing organisms present in the milk. In this process milk is heated at 62° temperature and cooled below 10°C.

Question 26.
In which months milk production is high?
Answer:
In the months of October and November milk production is high.

Question 27.
Who is the father of white revolution?
Answer:
Prof. J.K. Korian is the father of white revolution in India.

Question 28.
How is milk secreted?
Answer:
Milk is secreted from the mammary glands of animals.

Question 29.
Why do people in our country decorate their cattle during festivals?
Answer:
People believe that cattle are part and parcel of our culture. They treat them as their family members. So they decorate their cattle.

Question 30.
Why do some persons collect bones of dead animals?
Answer:
because bones are used in fertilizer industry.

Question 31.
What is the use of leather of animals?
Answer:
Leather of cattle is used in the leather industry.

Question 32.
What is Biogas? How is it produced?
Answer:
Biogas is produced from the wastes from cattle, home etc. As this is produced biologically, this gas is called biogas used for domestic purposes.

Question 33.
What are Broilers and layers?
Answer:
Broilers are the hens reared for meat and layers are the hens reared for eggs in poultry.

Question 34.
Name some local variety of poultry varieties.
Answer:
Aseel, Kadaknath, Chittagang, Longshan, Bursa are the pure local varieties.

Question 35.
What is a poultry?
Answer:
Production and rearing of hens on a large scale is called poultry.

Question 36.
In which place India is occupied in production of eggs?
Answer:
India achieved 4th position in the world by producing 41.06 million eggs per annum.

Question 37.
Name the foreign varieties of hens giving meat.
Answer:
New Hampshire, White plymouth, Rhode island red, while leg horn and Anoka.

Question 38.
What are the major practices in food production?
Answer:
Animal husbandry, poultry, fish culture, bee culture etc., are the major practices in food production.

Question 39.
In which months the egg prices are high?
Answer:
During January to April, egg prices are high.

Question 40.
Why egg prices are more in January to April?
Answer:
This is because of most of the eggs are used for hatching.

Question 41.
What is the temperature for hatchability of eggs?
Answer:
Hatchability of eggs is generally influenced by 37°C to 38°C temperature.

Question 42.
Write a slogan on nutritional Egg.
Answer:
“If you want to be healthy person eat egg every day”.

Question 43.
Name the traditional variety meant for fighting.
Answer:
Aseel (Berisa Kodi) is the Indian traditional variety meant for fighting.

Question 44.
How is hatching done in our rural areas?
Answer:
Our rural areas, the practitioner hatch eggs by placing them under broody hen.

Question 45.
What is the weight of Emu bird?
Answer:
The weight of Emu bird is nearly 50 kg.

Question 46.
What is the life span of natural wild varieties?
Answer:
Natural wild varieties grow fully in 5 to 6 years.

Question 47.
What is the life span of broilers?
Answer:
Broilers grow fully in just 6 to 8 weeks.

Question 48.
What is Apiculture?
Answer:
Culture of honey bees (apis) is called Apiculture.

Question 49.
What is the use of honey bee production?
Answer:
Development of apiculture is not only for honey production but also very much useful for crop pollination.

Question 50.
Which insects are the best pollinators?
Answer:
Honey bees are the best pollinators of many agricultural crops.

Question 51.
How much honey is produced by Indian honey bee?
Answer:
Indian honey bee produces 3 – 10 kg of honey.

Question 52.
Which honey bee is produces more honey?
Answer:
European honey bee produces 25 – 30 kgs of honey per annum.

Question 53.
Name the honey bees present in honey bee colony.
Answer:
A honey bee colony consists of one queen bee, several thousands of workers and few hundreds of drones.

Question 54.
What is the primary function of a queen bee?
Answer:
The primary function of a queen bee is to lay eggs.

Question 55.
What is the life span of a queen bee?
Answer:
The life span of queen bee is two-three years.

Question 56.
What are worker bees?
Answer:
The sterile females are called worker bees in the hive.

Question 57.
What is the function of worker bees?
Answer:
They attend to indoor duties during first three weeks of their lives such as secretion of royal jelly feeding of the brood, collecting nectar, pollen and water.

Question 58.
Name the plants that are sources of nectar.
Answer:
Fruit trees like citrus, apple, guava, tamarind, cultivated fields, crops like mustard, gingelly, wheat, cotton, sunflower.

Question 59.
What are the other products of Apiculture?
Answer:
Bee venom and bee wax are the other products of Apiculture.

Question 60.
How is bee venom used?
Answer:
Bee venom is used for the preparation of “Apistincture” used in homeopathic treatment.

Question 61.
What are the uses of bee wax?
Answer:
The uses of bee wax are production of polish cream, nail polish etc.

Question 62.
Name the parts present in a artificial bee hive.
Answer:
It consists of floor board, brood chamber, super chamber, top cover, inner cover, frames and entrance rod.

Question 63.
Name the pests and predators that attack honey bee colonies.
Answer:
Wax moths, wasps, rubber flies, dragon flies attack honey colonies. King crow, Bee eater are more harmful.

Question 64.
How are fish important for us?
Answer:
Fish constitute an important and rich sources of high quality animal protein.

Question 65.
What are the inland water areas?
Answer:
Rivers, fresh water and brackish water lakes, reservoirs, tanks, ponds, swamps etc., are the inland water areas.

Question 66.
Name the crustacean fishery.
Answer:
Prawns, lobsters and crabs together constitute the crustacean fishery.

Question 67.
Name the local varieties offish.
Answer:
Murrel (Korramenu), Katla (jalla), Katrana (bochalu), rohu (mosu), seer (vanjram) are the local varieties.

Question 68.
Name the marine fish varieties.
Answer:
Macerel, tuna, saradines are the marine fish varieties.

Question 69.
What are mechanized fishing?
Answer:
Fishermen catch fish by using machines is called mechanized fishing.

Question 70.
Name some marine fishes which are of high economic value.
Answer:
Mullets, Bhetki and peral spots, shel fishes such as prawns mussels and oysters as well as sea weed.

Question 71.
What are estuaries?
Answer:
Brackish water resources where sea water and fresh water mix together are called estuaries.

Question 72.
What is the reason for growing fish in paddy fields?
Answer:
The reason for this is increasing use of inorganic fertilizers and insecticides in paddy fields.

8th Class Biology 9th Lesson Production and Management of Food From Animals 2 Marks Important Questions and Answers

Question 1.
How do you appreciate the role of poultry to meet the food needs of the present day increasing population ?
Answer:

1. The world is facing the problem of over growth in population.
2. To meet the increasing population food needs, poultry is the best suitable option.
3. So billion hens are reared world wide for eggs and chicken.
4. India achieved 4th position in the world by producing 41.06 million eggs per annum.
5. India is placed in 5th position in the production of 1000 million kgs of chicken per year.
6. Hence, I appreciate the poultry, in fulfilling the food needs of the society.

Question 2.
“Fish has high nutrition values” said Shravya. Do you support Shravya? Why?
Answer:

1. The meat of fish contains 15-25% of proteins. Hence they are the rich sources of proteins.
2. The meat of fish has vitamins like A and D.
3. Fishes are the sources for very important fatty acids and unsaturated fatty acids which are very vital in our body’s metabolic activities.
4. Meat of fish can be easily digested. It helps in the growth and development.

Question 3.
Name the three Indian Major fresh water crops grown in fish culture.
Answer:

1. Rohu – Labeo rohita:
2. Boche – Catla catla
3. Erramosu – Cirrhinus mrigala are the three Indian major crop fishes.

8th Class Biology 9th Lesson Production and Management of Food From Animals 4 Marks Important Questions and Answers

Question 1.
This fish is called Tuna. Collect information about availability catching and marketing of this particular fish.

Answer:
Availability:
English: Big eye Tuna
Latin: Thunnus obesus
size + weight: Average today about 40 -180 c.m. about 1, 4-130 Kg.
Biggest Angled Fish: 197, 3 kg, 236 cm, Peru, 1957 Russel Lee
Maturity: Size 105 cm, weight 25 Kg., age 3 – 4 years
Maximum: Size 230 c.m., Weight 210 Kg., Age 15 years
Catching: 21% Eastern Pacific
38% Western Pacific
22% Indian Ocean
19% Atlantic Ocean
Catching Methods: Longlining, Purse seining and pole-and-line (by-catch)
Share of all Tuna: 2011 about 10% – 398.000 m.t
Main Production: Thailand, Philippines, Indonesia, Mexico, Venezuela, Ecuador, Colombia, Spain, Italy.
Life cyle: About 7-8
Major Markets: Japan (Sashimi)
Populr Product: Fresh (Whole fish)
Forms: Fresh Fillets (Sashimi)

Question 2.
Write a note on different methods used to store the fish in your area.
Answer:

1. The fish caught should be preserved in chilled conditions.
2. After catching the fish, gut is removed. Before transportation, fishes are thoroughly washed in clean and chlorinated waters.
3. They are perceived in insulated ice boxes with alternate layers of crushed ice and fishes in 1 : 1 proportion.
4. Preservation can also be done by
   a) Drying b) Salting c) Smoking d) Canning methods
5. Before canning, harmful bacteria like clostridum botulinum must be destroyed.
6. Cold storage facility and vans with refrigerated chamber have improved the storage and transport of fish.

Question 3.
Visit a poultry farm of your village. Collect the diseases of poultry and their preventive control measures. Prepare them in theform of a table.
Answer:

Diseases in Poultry birds	Casual organism	Precautionary control measures
Fowl cholera	Bacteria	Vaccination for fowl cholera is must.
Salmonellasis	Bacteria	Antibiotics with sulphur and vaccines.
Coryza	Bacteria	Sulfa drugs and antibiotics are necessary.
Fowl fox	Virus	They should be separated from the farm.
Ranikhet	Virus	Fowls should be separated from the farm and treatment should be given separately.

Question 4.
Write some diseases of tamed animals.
Answer:

1. Galikuntu is a common and dangerous diseases occur in cows and buffaloes.
2. Sheep and goats suffer from worm infections (Nattala vyadhi).
3. Some parasitic diseases cause damage to liver and intestine of tamed animals.
4. Viral and bacterial diseases also effect on milk production of cows and buffaloes.
   These are some examples for diseases in domestic animals.

8th Class Biology 9th Lesson Production and Management of Food From Animals Important Questions and Answers

Question 1.
How are the microorganisms like bacteria killed and how can the milk be preserved at milk chilling centres?
Answer:

1. Pasteurization of milk ensures the destruction of disease producing organisms present in milk.
2. In this process, milk is heated at 72°C for 30 minutes.
3. Prior to this, the milk was being cooled to below 10°C.
4. This process was invented by Louis Pasteur.

Question 2.
Dung is used as biofuel. You know that it is an accessory product. Write about such accessory products produced in animal husbandry.
Answer:
1. The supplimentary products produced from animal husbandry are meat, dung, leather, bones, horns, etc,
2. Animal husbandry is also contributing to different industries like

1. Dairy industry: Milk and milk products are produced.
2. Slaughter houses: Production of meat.
3. Leather industry: Tanning of leather and making shoes, belts and suitcases, etc.
4. Fertilizer industry : Bones of cattle are used in the production of chemical fertilizers.
5. Bio gas industry: Cattle dung is used in the production of biogas.
6. Toys industry: The horns of cattle are used to make toys and ornamental items.

AP State Syllabus AP Board 8th Class Biology Important Questions Chapter 8 Production and Management of Food From Plants

AP State Syllabus 8th Class Biology Important Questions 8th Lesson Production and Management of Food From Plants

8th Class Biology 8th Lesson Production and Management of Food From Plants 1 Mark Important Questions and Answers

Question 1.
What is Agriculture?
Answer:
The process of growing crops is called Agriculture.

Question 2.
What are long term crops ? What are short term crops?
Answer:
The crops which take 180 days or more for harvesting are called long term crops.
Ex: jowar, red gram etc.
The crops which takes 100 days for harvesting are called short term crops.
Ex: green gram, black gram etc.

Question 3.
What are Kharif crops?
Answer:
The crops grown in the rainy season are termed as Kharif. It starts from June to October.

Question 4.
What are Rabi crops?
Answer:
The crops grown in winter season are called Rabi. It starts from November to April.

Question 5.
When was rice cultivated?
Answer:
Rice was cultivated in the late Mesolithic period (9000 – 8000 BC) and in the Harappa cultivation (2,300 BC).

Question 6.
In which places Rice is grown as Kharif and Rabi?
Answer:
It is grown as a Kharif or a Rabi crop from Rajasthan to Arunachal Pradesh and from Kerala to Jammu and Kashmir.

Question 7.
What are the requirements for growing of paddy?
Answer:
Nature of the soil, humidity, rainfall, temperature.

Question 8.
Name the festivals that farmers celebrate.
Answer:
The sowing and transplanting is Akshaya Trithiya and harvesting associated with Pongal and Onam.

Question 9.
Name the activities that involve at the cultivation of paddy.
Answer:

1. Preparing the soil
2. Sowing the seeds
3. Applying manure
4. Facilitate water (irrigation)
5. Weeding
6. Crop harvesting
7. Storage.

Question 10.
What do farmers do to prepare the soil?
Answer:
Ploughing is done with a wooden plough and levelling will be done by using a soil plank being pulled by a pair of bullocks.

Question 11.
What is the scientific name of paddy?
Answer:
Oryza sativa which was named by Linnaeus.

Question 12.
What is the traditional good variety of rice?
Answer:
Molagolukulu is the traditional good variety which is grown in coastal areas of Nellore.

Question 13.
Name some traditional varieties of rice.
Answer:
Amrita sari, Bangaru Teega, Kolleti Kusuma, Potti Basangi, Sona Masuri.

Question 14.
Why do farmers do medication before sowing seeds?
Answer:
Medication is done to keep seeds away from the harmful microorganisms like bacteria, fungus etc.

Question 15.
What is broadcasting method?
Answer:
The method of dispersing seeds by sprinkling is called broadcasting method.

Question 16.
What is transplantation?
Answer:
When the plants grow to certain height, farmers pick out the seedlings from the plot and make bundles. These plants are sown in proper distances. This is called transplantation. (Naru etlu)

Question 17.
What is a paddy planter?
Answer:
A paddy planter is useful for farmers those who cultivate paddy in large areas, to maintain proper distance sowing the seedlings.

Question 18.
Name some pests that attack rice plants.
Answer:
Moth caterpillars, paddy beetles and their larva, paddy grasshoppers and aphids.

Question 19.
What are the appliances used to spray pesticides?
Answer:
Sprayers and dusters.

Question 20.
Name the crops that are affected by fungus.
Answer:
Wheat, paddy and sugarcane are generally affected by fungus.

Question 21.
Name the fungal disease in groundnut.
Answer:
Groundnut is attacked by a fungal disease called Tikka disease.

Question 22.
What are the symptoms of tikka disease?
Answer:
All leaves of the affected plant have powdery spots. The whole plant becomes wilted.

Question 23.
Name some diseases that affect lemon tree.
Answer:
Viral diseases, bacterial diseases, leaf miner, citrus butterfly and fungal diseases.

Question 24.
How can the pests will be controlled?
Answer:
A farmer removes the affected leaves from the plant and put them in a dump and covers with soil to control the pests.

Question 25.
How can you identify that the plant is affected by fungus?
Answer:
A fungal infection is usually seen as white, black, yellow, brown spots or a fluffy or powdery coating on leaves.

Question 26.
Name some garden pesticides.
Answer:
Garden pesticides are derived from plants like neem, tobacco and chrysanthemum are less dangerous to other living things.

Question 27.
Name some organic synthetic pesticides.
Answer:
The organic synthetic pesticides commonly used are DDT (Dichloro diphenyl trichloro ethane) BHC (Benzene Hexa Chloride), Chlordane, Endrin, Aldrin, Endosulfan and Diazinon.

Question 28.
Who wrote a book on the dangers of pesticides?
Answer:
In 1960 Rachael Carson wrote a book called ‘silent spring’ in which she wrote the dangers of pesticides.

Question 29.
How are biofertilizers formed?
Answer:
Biofertilizers are formed by decomposing plant and animal wastes.

Question 30.
Why do farmers add manure to the soil?
Answer:
If the farmer grows same type of crops in the same field every year the nutrients of the soil decrease crops do not give good yield. So, farmers add manure for healthy growth of plants.

Question 31.
Name some chemical fertilizers.
Answer:
Urea, D.A.R, superphosphate, potash,which are enriched with nitrogen, phosphorous and potash.

Question 32.
What is irrigation?
Answer:
The process of watering crop plants in the field is known as irrigation.

Question 33.
What is furrow irrigation?
Answer:
The water is allowed to enter the field through channels or furrows made between two rows of crop is furrow irrigation.

Question 34.
What is basin irrigation?
Answer:
In this method of irrigation the field is just filled with water as in the case of paddy. Canals, tanks and wells are the water sources. Farmers dig small canals from tank to fields to supply water.

Question 35.
Why is water logging harmful?
Answer:
Water logging is harmful because it does not allow the roots to breathe.

Question 36.
What is drip irrigation method?
Answer:
This method is employed when the availability of water is poor. The water reaches the plants drop by drop.

Question 37.
Why should the weeds be removed?
Answer:
The weeds compete with the primary crops for nutrients, water and light and the prime plants may not grow. Hence weeds should be removed.

Question 38.
What is harvesting?
Answer:
Collecting grains from the crop by cutting the matured plant is called harvesting.

Question 39.
Why is storage of grain is an important task?
Answer:
We do not consume the entire crop at a time. They can be damage by fungi, pests, rats and bacteria. To over come this problem farmers dry the grains in sun and store the grain in jute bags, metallic and bamboo bins.

Question 40.
What is global grain?
Answer:
Rice is the prime, most essential and important staple food crop. It is also called global grain as it is grown all countries in the world.

8th Class Biology 8th Lesson Production and Management of Food From Plants 2 Marks Important Questions and Answers

Question 1.
What is a paddy planter? What is its use?
Answer:

1. Paddy planter is the latest machine used for sowing the seedlings.
2. It is useful for large scale cultivation of paddy.
3. It is easy to maintain proper distance sowing the seedlings.
4. Paddy planter is a device which save both time and money to the farmer.

Question 2.
Arrange the sequence of events in the cultivation of paddy crop.

Answer:

Question 3.
Give different methods of irrigating a crop in the field.
Answer:

1. Lift irrigation
2. Swinging basket
3. Water wheel
4. Tube well
5. Sprinkler
6. Drip irrigation

Question 4.
Draw and write the names of diseases that affect plants.

Answer:

1. Virus in rice plant
2. Tikka disease in groundnut

Question 5.
What are the advantages of ploughing in summer?
Answer:

1. It improves the air circulation.
2. Replacing the soil layers.
3. Reduce the weeds and diseases.
4. It improves the soil health.
5. Roots are easy to penetrate in to the soil.

8th Class Biology 8th Lesson Production and Management of Food From Plants 4 Marks Important Questions and Answers

Question 1.
Collect the information from farmers about different crops and their sowing methods.
Answer:

Question 2.
Draw and label the diagram of sprouting paddy seeds.
Answer:

Question 3.
Take some paddy grains and soak them in water for one day. Take them into watch glass and sow them in soil. After that observe the radicle and plumule with the help of hand lens and draw the picture of it.
Answer:

8th Class Biology 8th Lesson Production and Management of Food From Plants Important Questions and Answers

Question 1.
Give two examples of plants that grow with transplanting (Natlu veyadam).
Answer:
Paddy, wheat, chilli.

Question 2.
A farmer cultivated cotton crop in his field. He did not get sufficient yield. Guess any four causes for it.
Answer:

1. The crops grown in the rainy season are termed as “Kharif”.
2. Kharif season is from June to October.
3. Examples for Kharif crops are paddy, sugarcane, jowar and turmeric, etc.
4. The crops that are grown only in winter season are called Rabi crops.
5. Rabi season is from October to March.
6. Examples for Rabi crops are wheat, maize, coriandrum, fenugram, barli, etc.

Question 3.
Look at the picture and answer the following questions.

a) Which type of fertilizer is this?
b) What are the chemicals present in this?
c) What does 20-5-10 indicates?
d) Is it profit or loss by using this type of fertilizers? Why?
Answer:
a) Chemical fertilizer
b) Nitrogen (N), Phosphorus (P), Potash (K)
c) 20% of Nitrogen
5% of Phosphorus
10% of Potash
d) If we use chemical fertilizers for a longer period, soil health will be damaged. So, we should not use chemical fertilizers.

Question 4.
Study the following table and answer the questions.

Name of the plant disease	Causative Microorganism	Mode of Transmission
Tobacco mosaic	Virus	Insects
Red rot of sugarcane	Fungi	Air, seedlings
Citrus canker	Bacteria	Air
Tikka disease of groundnut	Fungi	Air, seeds

a) What are the diseases caused by fungi in plants?
b) What are the diseases Transmitted through air?
c) Which microorganisms cause Tikka disease of groundnut?
d) How virus transmit mosaic disease in tobacco?
Answer:
a) Red rot of sugarcane, Tikka disease of groundnut.
b) Red rot of sugarcane, citrus canker, Tikka disease of groundnut.
c) Fungus.
d) Through insects.

Question 5.
What is the similarity between sprinklers and drip irrigation?
Answer:
Sprinklers and drip – irrigation techniques are used in low water available soils. They are very useful for the farmers who are cultivating crops in dry lands. These are called as “micro – irrigation methods”.