ICSE Living Science Biology for Class 8 Solutions Chapter 6 Production of Food and its Management
Check Your Progress 1
Fill in the blanks.
Question 1.
……………… crops are grown in winter season.
Answer:
Rabi crops are grown in winter season.
Question 2.
Soil acidity can be reduced by adding …………………
Answer:
Soil acidity can be reduced by adding lime.
Question 3.
In …………… irrigation water is sprayed on the standing crops in the form of artificial rain.
Answer:
In sprinkler irrigation water is sprayed on the standing crops in the form of artificial rain.
Question 4.
…………… and…………. are phosphatic fertilizers.
Answer:
Ammonium and superphosphate are phosphatic fertilizers.
Question 5.
………….. was the first instrument to be used for harvesting.
Answer:
Hand sickle was the first instrument to be used for harvesting.
Check Your Progress 2
Fill in the blanks.
Question 1.
…………… are chemicals used to kill insects.
Answer:
Insecticides are chemicals used to kill insects.
Question 2.
Hybridization results in production of ……….. and ………….. adapted varieties.
Answer:
Hybridization results in production of vigorous and better adapted varieties.
Question 3.
………….. is obtained from red algae.
Answer:
Agar is obtained from red algae.
Question 4.
Alcohol and alcoholic drinks are produced by a process called …………. of cereals.
Answer:
Alcohol and alcoholic drinks are produced by a process called fermentation of cereals.
Question 5.
AH animals domesticated by humans for their usefulness constitute ……………….
Answer:
All animals domesticated by humans for their usefulness constitute livestock.
Question 6.
…………………… helps in building-up of haemoglobin.
Answer:
Honey helps in building-up of haemoglobin.
A. Tick the most appropriate answer.
Question 1.
Which of these crops is not a cereal ?
a. Wheat
b. Rice
c. Maize
d. Pea
Answer:
d. Pea
Question 2.
Humus content is maximum in this type of soil,
a. Laterite soil
b. Mountain soil
c. Alluvial soil
d. Desert soil
Answer:
b. Mountain soil
Question 3.
The process of loosening and turning the soil is called
a. levelling
b. harvesting
c. ploughing
d. winnowing
Answer:
c. ploughing
Question 4.
It is a type of irrigation in which water from a canal is allowed into the field.
a. Flood irrigation
b. Basin irrigation
c. Drip irrigation
d. Sprinkler irrigation
Answer:
b. Basin irrigation
Question 5.
Which of these is a mixed fertilizer (complex) ?
a. Potassium chloride
b. Urea ammonium phosphate
c. Sodium nitrate
d. Superphosphate
Answer:
b. Urea ammonium phosphate
Question 6.
Which of these is a weedicide ?
a. Superphosphate
b. 2, 4-D
c. Urea
d. parathion
Answer:
b. 2, 4-D
Question 7.
IR-8 is a variety of
a. wheat
b. rice
c. pulses
d. bajra
Answer:
b. rice
Question 8.
Sonalika is a high-yielding variety of
a. rice
b. wheat
c. maize
d. bajra
Answer:
b. wheat
Question 9.
Which of the following is a disease of cattle ?
a. Rinderpest
b. Fowlpox
c. Aspergillosis
d. Ranikhet
Answer:
a. Rinderpest
Question 10.
Foot and mouth disease occurring in cattle is caused by
a. bacteria
b. fungus
c. virus
d. protozoa
Answer:
c. virus
Question 11.
Poultry products are a rich source of –
a. animal proteins
b. sugar
c. plant proteins
d. carbohydrates
Answer:
a. animal proteins
Question 12.
It is an example of a disease amongst poultry birds,
a. Rinderpest
b. Anthrax
c. Aspergillosis
d. Foot and mouth
Answer:
c. Aspergillosis
Question 13.
Aspergillosis is a disease occurring in birds caused by a –
a. bacterium
b. fungus
c. virus
d. alga
Answer:
b. fungus . :
Question 14.
A place containing a number of beehives in which bees are kept and bred is called an
a. hatching
b. apiary
c. apiculture
d. apiarist
Answer:
b. apiary
Question 15.
Care and management of honeybees is called
a. horticulture
b. apiculture
c. sericulture
d. pisciculture
Answer:
b. apiculture
B. Fill in the blanks.
Question 1.
The implement used to turn over and breakup soil is called ………….
Answer:
The implement used to’ turn over and breakup soil is called plough.
Question 2.
The sowing of seeds by hand at random is called ………….
Answer:
The sowing of seeds by hand at random is called broadcasting.
Question 3.
Allowing a field to remain free of crops for on or more seasons is called ………….
Answer:
Allowing a field to remain free of crops for orte br more seasons is Called field Tallow.
Question 4.
The removal of unwanted plants from the field is called ………….
Answer:
The removal of unwanted plants from the field is called weeding.
Question 5.
The process of separating the grain from the chaff is called………….
Answer:
The process of separating the grain from the chaff is called winnowing,
Question 6.
During storage of grains, …………. causes degradation of stored food materials.
Answer:
During storage of grains, moisture ladden air causes degradation of stored food materials.
Question 7.
Any organism which damages or destroys a crop plant is called a …………
Answer:
Any organism which damages or destroys a crop plant is called a pest.
Question 8.
The use of ………….. is one of the effective methods of controlling insect pests and crop diseases.
Answer:
The use of pesticides is one of the effective methods of controlling insect pests and crop diseases.
Question 9.
………… is one of the commonly used insecticides.
Answer:
BHC is one of the commonly used insecticides.
Question 10.
Chemicals used to kill rodents are called ………….
Answer:
Chemicals used to kill rodents are called rodenticides.
Question 11.
Cattle feed consists of two types of ingredients ………… and ……………
Answer:
Cattle feed consists of two types of ingredients roughage and concentrate.
Question 12.
………….. is a common disease of cattle.
Answer:
Foot and Mouth is a common disease of cattle.
Question 13.
Pigs get easily infected with ……….. which can be transferred to humans.
Answer:
Pigs get easily infected with tapeworms which can be transferred to humans.
Question 14.
………….. is the rearing and large-scale production of fish.
Answer:
Pisciculture is the rearing and large-scale production of fish.
Question 15.
The rearing of silkworm is known as
Answer:
The rearing of silkworm is known as scriculture.
C. Define the following.
1. agriculture
2. irrigation
3. weeding
4. threshing
5. hybridization
6. pisciculture
7. apiculture
8. sericulture
Answer:
1. agriculture – The branch of science that deals with the growing plants and raising lifestocks of human use is called agriculture.
2. irrigation – Irrigation means supplying water to the crops in the fields at specific intervals.
3. weeding – The process of removing weeds (unwanted and uncultivated plant) from the field is called weeding.
4. threshing – Separating the grains from the cut crop is called threshing.
5. hybridization – The process of cross breeding two or more varieties of plants or animals to get variety with
desirable characteristics is called hybridization.
6. pisciculture – The process of rearing, breeding and management of fishes on a large scale is called
pisciculture.
7. apiculture – The care, breeding and management of honeybees for commercial purpose is called apiculture.
8. sericulture – The breeding and management of silkworms for the production of silk is known as
sericulture.
D. Give two examples of each of the following.
1. fertilizers
2. weeds
3. weedicides
4. insecticides
Answer:
1. fertilizers –
(i) Nitrogenous fertilizer (sodium nitrate, urea)
(ii) Potassium fertilizers (potassium chloride, potassium nitrate)
2. weeds – wild oat grass Amaranthus.
3. weedicides –
(i) 2, 4-1
(ii) metachlor
4. insecticides –
(i) malathion
(ii) parathion
E. Match the name of the animal in Column A with the appropriate breed in the Column B.
| Column A (Animal) | Column B (Breed) |
| 1. Cow (indigenous breed) | a. Bikaneri |
| 2. Cow (hybrid) | b. HH-260 |
| 3. Buffalo | c. Gir |
| 4. Hen (desi breed) | d. Karan-Swiss |
| 5. Hen (exotic breed) | e. Murrah |
| 6. Hen (hybrid) | f. Pashmina |
| 7. Goat | g. White leghorn |
| 8. Sheep | h. Aseel |
Answer:
| Column A (Animal) | Column B (Breed) |
| 1. Cow (indigenous breed) | c. Gir |
| 2. Cow (hybrid) | d. Karan-Swiss |
| 3. Buffalo | e. Murrah |
| 4. Hen (desi breed) | h. Aseel |
| 5. Hen (exotic breed) | g- White leghorn |
| 6. Hen (hybrid) | f. Pashmina |
| 7. Goat | b. HH-260 |
| 8. Sheep | a. Bikaneri |
Match the terms given in column A with those in column B.
| Column A | Column B |
| 1. Sericulture | a. Rearing of fish |
| 2. Apiculture | b. Cattle |
| 3. Pisciculture | e. Fowl |
| 4. Anthrax | d. Rearing of honeybees |
| 5. Ranikhet | e. Rearing of silkworms |
| 6. Animal hubandry | f. Rearing of animals |
Answer:
| Column A | Column B |
| 1. Sericulture | e. Rearing of silkworms |
| 2. Apiculture | d. Rearing of honeybees |
| 3. Pisciculture | a. Rearing of fish |
| 4. Anthrax | b. Cattle |
| 5. Ranikhet | e. Fowl |
| 6. Animal hubandry | f. Rearing of animals |
G. Write short answers.
Question 1.
What are rabi crops ? Name any two.
The crops grown in winter season are known as rabi crops. Sowing is done at the beginning of winter and the crop is harvested in March or April. Wheat, niustard, potato are Rabi crops.
Question 2.
How is red soil different from black soil ?
Answer:
Red soil :
- The colour of soil is red due to presence of iron oxide.
- It is rich in clay content and is well drained and poor in humus.
Black soil :
- It is rich is iron and magnesium derived from basaltic rocks.
- It is clayey, contains dead organic matter and water.
Question 3.
Define crop rotation.
Answer:
The practice of growing different crops in different seasons in rotation so that the soil is not depleted of its nutrients is called crop rotation, if the same crop is grown in a field year after year the fertility of the soil goes on decreasing so to replenish soil with nutrients crop rotation is done.
Question 4.
What is weeding ?
Answer:
Weeds reduce crop yield, as they compete with the crops for water, minerals and sunlight. So it is necessary to remove them from the fields from time of time. The removal of weeds from a field is called weeding.
Question 5.
What is basin irrigation ?
Answer:
The field is made in to a basin-like structure. Bunds (Earthen embankment) or ridges are constructed around the areas forming basin. It is used for crops requiring well-irrigated conditions and large quantity of water.
Question 6.
Give two examples of marine water fishes.
Answer:
Fishes living in marine water are Hilsa, Pomphret, Salmon, Sardine, Tuna and Bombay duck.
H. Answer in detail.
Question 1.
Differentiate between kharif and rabi crops.
Answer:
Kharif crops
- Crops grown in summer season (beginning of monsoon season) are called Kharif Crops,
- These are sown in June or July and harvested in September or October.
- Example : Rice maize, groundnut, Jute, cotton.
Rabi crops :
- Crops grown in winter season are called Rabi Crops.
- These are grown in October or November and harvested in March or April.
- Example : Wheat, mustard, potato, barley and gram.
Question 2.
List the different agricultural tasks performed by a farmer.
Answer:
The various agricultural tasks, which a farmer performs for healthy and good crop yield are as follows :
- Preparation of soil : Firstly the soil is prepared by ploughing and tilling for sowing the seeds.
- Selection and sowing of seeds : Healthy seeds are selected for sowing. Sowing of seeds is done either by broadcasting or using seed drill.
- Irrigation : For the survival and proper development of crop plants, water is necessary. Fields are irrigated by means of rivers, lakes or by drawing groundwater with the help of tubewells.
- manuring : improving the fertility of soil by using natural fertilizers called manures and artificial fertilizers.
- weeding : unwanted plants are removed by using trowel or a harrow or by spraying weedicides this process is called weeding.
- protection from pests and diseases : Crop is protected from the pests and diseases by using pesticides.
- harvesting : once a crop is mature farmers cut it and gather it. The process of cutting and gathering of crops is called harvesting.
- storage of grains : Crop produced is stored, so that it can be made available in different parts of the country throughout the year.
Question 3.
What are the advantages of ploughing ?
Answer:
a. It aerates the soil, that is, soil particles become loose and air can enter between them. This helps the roots of the plant to breathe easily.
b. It helps in the penetration of roots of seedlings.
c. It improves soil drainage.
d. It uproots weeds and kills them.
e. Dead organic matter is ploughed deeper into the soil, allowing faster decomposition.
f Loose soil aids the growth of microbes and other organisms. These provide nutrients to the soil.
g. Loose soil mixes uniformly with fertilizers.
Question 4.
What are the different ways of sowing seeds ?
Answer:
Seeds can be sown by two different methods.
a. Broadcasting : The first is by scattering the seeds by hand. It is also called broadcasting. But this results in unequal distribution of seeds and may not get planted at the correct depth. If planted deep in the soil, they cannot respire and their shoots may not be able to push through the soil. If planted on the surface, they will be eaten by birds.
Seed drill : The other method is to use a seed drill A seed drill is a metal tube that pokes a hole in the ground. The farmer drops seeds into the hole, and then covers it up. It ensures that the seeds are properly spread and that the seeds go into the soil up to the right depth.
Question 5.
Explain the different ways in which fields are irrigated?
Answer:
Flood or tubewell irrigation : Flood irrigation is used where the land is flat and levelled. Water from an irrigation pump or tubewell is allowed into the field from a high level It is a wasteful method and is used only when water is available in plenty.
a. Furrow irrigation : It is a form of surface irrigation. Water is confined to furrows. It is frequently used for row crops. The field is made into a number of ridges and furrows. The crop is raised on the ridges and irrigation is practiced in the furrows. This method is used for crops which do not require large quantity of water.
b. Basin irrigation : The field is made into a basin-like structure. Bunds (earthen embankment) or ridges are constructed around the areas forming basin. It is used for crops requiring well-irrigated conditions and a large quantity of water. It is also a form of surface irrigation.
c. Sprinkler irrigation : Water is sprayed on the standing crops in the form of artificial rain. This method is used where flood or furrow irrigation is impractical.
d. Drip irrigation ; This is the latest development in irrigation systems. Small amount of water is allowed to trickle slowly into the soil through mechanical devices. In this method pipes are fitted with small tubes, called emitters, and laid under the soil in the root zone of the plants. The water from these emitters is released drop by drop into the soil around the roots. If a field is supplied with excess water it is said to be waterlogged. This reduces the supply of air to the roots and stops growth of plants,
Question 6.
Describe the various natural methods of replenishing soil.
Answer:
a. Field fallow : One way of allowing land to regain the nutrients naturally is to leave it free (or fallow) for one or more*Reasons, Dead plants, animals and other organic matter that collect on the land are decomposed by microbes. Thus, the nutrients are returned,to the soil.
b. Crop rotation : Each crop uses more of some nutrients and less of others. Farmers, therefore, change their crop in each season so that the soil is not depleted of any particular nutrient. This practice of growing crop is called crop rotation. For example, wheat and rice use up large amounts of nitrogen from the soil. This nitrogen can be naturally replenished if the next crop grown is that of a legume, like pea and groundnut. Leguminous crops use nitrogen of the air to make nitrates, which replenish the soil with usable nitrogen. The soil is then ready for the next wheat or rice crop.
c. Mixed cropping : Sometimes two or more crops are grown together in the same field. The crops are chosen in such a way that die products and waste materials from one crop help in the growth of the other. Cotton and groundnut crops are often grown together for this reason.
However, these natural methods alone are not sufficient to maintain the fertility of the soil, and farmers have to add manures arid fertilizers from time to time.
Question 7.
How are manures different from fertilizers ?
manures :
- A natural substance obtained by the decomposition of plants and animals.
- Prepared in fields
- Provides a lot of humus to the soil
- Less rich in nutrients. šo required in large quantities.
- Nõ pollution is caused.
Fertilizers :
- These are chemical fertilizers.
- Prepared in factories.
- Does not contain any humus.
- Rich in specific nutrients, šo re4uired in very small quantities.
- Causes water pollution.
Question 8.
How is compost prepared ?
Answer:
a. Cörnpost : Compost is a maiure prepáred from farm and town waste like vegetable and animal waste, sewage waste, weeds and straw. Compost is made by buçying all the waste ¡n’a pit with alternate layers of soil This organic nmtter is decomposed by both aerobic and anaerobic microorganisms. This process is called composting. Compost is rich in organic nutrients hut not as important as nutrients like nitrogen, phosphorus and potassium.
Question 9.
What are biofertilizers ?
Answer:
Biofertilizers : There are certain beneficial microorganisms which enrich the soil by fixing atmospheric nitrogen and dissolving mineral nutrients present in the soil. These are called biofertilizers. These microorganisms are cultivated, packed and supplied to the farmers who mix them in soil as per requirement.
Question 10.
How is storage of food beneficial ?
Answer:
Food grains as well as other products obtained from the crops need to be stored after harvesting.
Proper storage helps in the following ways.
a. If ensures availability of food throughout the year.
b. It helps in easy transportation of food to far off places.
c. It helps in preventing infestation of grains by insects and fungi.
d. It helps in maintaining buffer stock for emergency which may arise due to crop failure or natural calamity.
Question 11.
How is excessive use of pesticides harmful for human beings ?
Answer:
Although these chemicals are useful, they should be used with care. In human beings, they irritate the skin and cause respiratory problems. They mix with the soil and water and are absorbed by the plants. They enter our body through fruits and vegetables and can be harmful for the body. Fruits and vegetables should be washed thoroughly before eating otherwise they might affect our health over a period of time.
Question 12.
List the advantages and disadvantages of hybridization.
Answer:
Advantages of hybridization :
(i) It makes possible to develop varieties that are disease resistant and pest resistant.
(ii) Varieties that give higher yield and have early maturity quality are developed by this technique.
Hybridization results in production of vigorous and better adopted varieties.
Disadvantage of hybridization :
(i) It is a tedious, time consuming process which can be done by a plant breeder only.
(ii) Sometimes hybrids produced may be sterile.
Question 13.
How are bacteria useful to human beings ?
Answer:
a. Saprophytic bacteria decompose excretory products and dead remains of plants and animals into simple substances. Thus, they clear the earth of all the waste. These bacteria are called decomposers. They are the natural scavengers which help in cleaning the earth.
b. Bacteria along with certain fungi play an important role in maintaining the fertility of the soil. Some bacteria live in the root nodules of plants, such as pea, gram and beans. These bacteria absorb the nitrogen of the atmosphere and convert it into nitrates which are used by the plants.
c. The digestive tract of animals like cows, sheep and camel consists of bacteria that break down cellulose of the plant into simple sugars which are readily absorbed by the animals.
d. Manufacture of vinegar, curd and cheese involves the activity of bacteria. Bacteria are also used in the production of tea, coffee and cocoa. Some industrial products, such as lactic acid, citric acid, and alcohol are obtained by the action of bacteria.
e. Bacteria are also involved in tanning of leather. Separation of fibres from the rest of the tissues of fibre plants, such as flax, jute is called retting of fibres. This is brought about by the action of bacteria on plant parts submerged in water.
f. Certain medicines like antibiotics and vitamin B-complex tablets are manufactured with the help of bacteria.
Question 14.
List five ways in which fungi help mankind.
Answer:
a. They are nature’s scavengers. They decompose the dead, decaying bodies of plants and animals and their- waste products. This also helps in making the soil fertile.
b. Morels and some mushrooms are enjoyed as palatable food.
c. Yeast is used in the production of wine and bakery products. For baking bread, yeast along with a little sugar is mixed with Hour to make dough. The dough is kept in a warm place. The yeast uses the sugar present in the dough as food. During this process of breaking down of sugar, carbon dioxide and alcohol are formed and they make the dough rise. When the bread is baked, alcohol and carbon dioxide escape from the loaf making it light and fluffy.
d. Idli and dosa are made from a mixture of ground dal and rice. After a few hours the mixture rises and becomes light, fluffy and sour. This is because of the action of bacteria.
e. Yeast is also used for manufacturing vitamins. Penicillin, an antibiotic is obtained from Penicillium which is effective in destroying many kinds of disease-causing bacteria.
f. Alcohol and alcoholic drinks are produced by a process called fermentation of cereals by yeast. Wine is prepared by fermentation of grapes, and beer by fermentation of barley.
Question 15.
Which type of food ensures good milk production in cattle ?
Answer:
The milk-yield of animals depends on the amount and the kind of food provided to them. Cattle feed consists of two types of ingredients – roughage and concentrate.
a. Roughage : It includes, straws of cereals (hay), green fodder, silage and so on which has more of fibrous substance than nutritive value.
b. Concentrate : It includes substances which are rich in one or more nutrients. These are provided by grams and seeds of bajra, maize, cotton seeds, oil cakes, rice and wheat bran.
Living Science Biology Class 8 ICSE Solutions