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Wednesday, 12 September 2018

Class 8th : Science - Chapter 6 : Food Production and Management

Book Cover Science - 8th

Chapter 6: Food Production And Management
I. Name the Following:
1. Five requirements essential for obtaining good crop production.
Ans. Five requirements essential for obtaining good crop production are:
i. Right kind of soil, ii. Good quality seeds, iii. Required amount of water, iv. Protection from weeds, and v. Proper implements.
2. Two types of fertilizers:
Ans. Nitrogen and Potash fertilizers.
3. Some chemicals used to protect crops from insects, pests and weeds.

Ans. Insecticides such as malathion, dimecron, and polythion (Insects), Pesticides such as parathion, malathion, BHC (Benzene Hexachloride) (Pests) and Weedicides such as simazine (Weeds).
4.  Some animal products.
Ans. Milk, egg, meat, honey, fish oil are some animal products.
5. Members of a colony of a bee.
Ans. Workers; which are sterile females, Drones; which are fertile males, and a queen which is a fertile female.
II. Fill in the blanks.
1.  A weedicide is used to remove the weeds from the soil.
2. A clod crusher is used to trowel the soil by breaking the lumps of soil after preliminary ploughing.
3. Kharif crops are sown during the months of June and July.
4. Paddy seeds are not sown directly into the soil.
5. Rabi crops are harvested during the months of March and April.
6. The practice of taking the seedlings from the nursery to the field is known as transplanting field.
7. Pearls are used in jewellery.
8. Honey contains 17% water and 78% sugar with minerals.
9. The hen-houses are called pens.
10. Murrah Jaffarabadi are well known breeds of buffaloes.
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III. Answer the following figure in only one word or in figure:
1. What is the process of turning and loosening the soil called?
Ans. Tilling or Ploughing.
2. Which implement is used for tilling soil?
Ans. Plough
3. Which implement is used for breaking up the large lumps of soil?
Ans. Clod Crusher
4. What is the implement used for sowing called?
Ans. Seed Drill and Broadcaster
5. What is the top part of the drill called?
Ans. Seed Bowl
6. What is an egg-laying bird called?
Ans. Brood Hen
7. Name the members of the bee colony.
Ans. Workers, Drones and Queen
8. Which material is used to cover the floor of a hen-house?
Ans. Straw.
9. Which is the common food of poultry chicken?
Ans. Grains
10. Which bee is responsible for laying eggs?
Ans. Queen bee
IV. Give the scientific reasons for the following:
1. Grains, pulses, vegetables and fruits should be used in our daily life?

Ans. Our body needs essential elements for proper growth and maintenance. These elements can be obtained from grains, pulses, vegetables and fruits. These elements together make a balanced diet which is essential to make our body healthy.
2. The soil should be loosened before seeds are sown?
Ans. The soil should be loosened before seeds are sown so that to ventilate the roots and roots of the young plant can penetrate it easily.
3. Seeds should be sown at a proper depth in the soil?
Ans. Seeds should be sown at a proper depth in the soil so that they can germinate more easily.
4. Fruits and vegetation should be washed thoroughly before eating?
Ans. Fruits and vegetation should be washed thoroughly before eating because they have a coating of pesticides or certain chemicals that can be harmful for us.
5. Grains are dried thoroughly before they are stored?
Ans. Grains should be dried before they are stored because wet or moisten seeds spoil when kept in storage places.
V. Answer the following questions:
Q1. What are the requirements of farming which would lead to high yields of crops?
Ans. Following are the requirements of farming to get the high yield crops:
i. The field should be open so that sunlight and air are abundantly available.
ii. The field should be protected from cattle and other domestic animals that may destroy crops.
iii. The soil should be tilled before sowing seeds to ventilate the roots and and roots of the young plant can penetrate it easily.
iv. The right amount of water should be available.
v. The soil should contain sufficient amount of nutrients for the healthy growth of plants.
vi. Unwanted plants (weeds) should be removed from the soil so that the main plant gets enough nutrients.
Q2. What is tilling? How is it done?
Ans. Loosening or turning over of soil by a plough before sowing seeds is called tilling. It is done by a plough made of wood and iron driven by animals. Tractors are also used for tilling the fields.
Q3. Write a short note on the process of sowing?
Ans. The process of sowing of seeds starts after the land is fully prepared for sowing. Sowing is done by two methods. First method is broadcasting, by which seeds are sown by hand or by a broadcaster. The second method of sowing is by using seed drills. The seed drill consists of a vertical tube with a seed bowl which is tied to a plough. The farmer drops the seeds into the bowl while ploughing.
Q4. What are manures? Discuss their important types?
Ans. Manures are organic materials which supply all the elements a plant needs in small elements. The manures add organic matter to the soil which increases water-holding capacity in sandy soil and drainage in clayey soil.
Important Types of Manures:
Farmyard Manure (FYM): It is the most valuable manure made from the organic matter such as remnants of straw, leaves and excreta of cattle. It is commonly applied to the soil to make it fertile and soft.
Green Manure: It is made from the leaves of green plants. This improves the physical structure as well as soil fertility.
Compost Manure: It is a rotten mixture of all the cattle shed wastes and all the available refuse.
Q5. What is a fertilizer? Explain its importance.
Ans. A fertilizer is an inorganic material mainly used to increase the essential elements in the soil. For example, nitrogen, phosphate and potash
Q6. What are broadcasting and transplanting?
Ans. The method by which seeds are sown by scattering in hand or by a broadcaster is known as broadcasting. The practice of taking the seedlings from the nursery to the main field is known as transplanting.
Q7. What is the difference between manure and fertilizer?
Ans. Manures are organic materials of decomposed leaves, straw and animal excreta while as fertilizers are inorganic materials of certain chemicals.
Q8. Why are weeds harmful? What is used to remove them?
Ans. Weeds are harmful because they grow around the crops and use their nutrients as their food for growth thus reduce the growth and yield of crops. Weeds are removed either manually or by spraying weedicides like simazine or 2,4-D (2, 4-dichlorophenoxy acetic acid).
Q9. What are insecticides? Give examples.
Ans. Insecticides are insect killing chemicals to protect crops from harmful insects. For example, malathion, dimecron and polythion.
Q10. How do insecticides protect crops?
Ans. Insecticides protect plants by killing insects or pests as well as their larvae around crops without affecting crops.
Q11. Which are the two main seasons in India for cultivating crops?
Ans. In India there are two main seasons for cultivating crops: Kharif season in which crop is sown in June and July and harvested after monsoon season, and Rabi season, in which crop is sown in October to December and harvested in March or April.
Q12. Name some harvest festivals of India?
Ans. Pongal, Baisakhi, Holi, Diwali, Nabanya and Bihu are some harvest festivals of India.
Q13. Name four factors responsible for the improvements of crops.
Ans. Plant breeding, Soil improvement, Protection from pests and weeds and Storage are the four factors responsible for the improvements of crops.
Q14. Write short note on the process of harvesting.
Ans. Harvesting is the process of cutting and collecting the matured crop from the fields. This may be done either by hand or with a sickle or with machines known as combines or harvesters.
Q15. Why does a farmer rotate crops in the field?
Ans. Because rotation of crops add minerals of the soil. It makes the soil more fertile to produce more crop yield.
Q16. What do you understand by mixed crops?
Ans. The method of growing crops together to save time and labour is known as mixed crops. Crops like ground and crops are grown together and are called mixed crops.
Q17. Why are fields sometimes allowed to remain fallow?
Ans. Fields are sometimes allowed to remain fallow to increase the humus and micro-organisms in the soil so that to replenish the nutrients of the soil.
Q18. List the importance of fish in our lives.
Ans. Fish provides proteins. Its oil is used for many purposes. Fish is used to cure many diseases.
Q19. What is the nutrient value of honey?
Ans. Honey contains 17% water and 78% 0f sugar with minerals and enzymes which help in digestion of food.
Q20. How are domesticated animals useful to us?
Ans. Domesticated animals are useful to us because they provide many things for our day to day life. Such as, Cows, goats, sheep etc. provide milk and meat. Horses and camels are used to carry loads. Hens provide eggs and meat.
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ADDITIONAL TEXT BOOK QUESTIONS
WORKSHEET: 6.1
Q1. Name various sources of food.
Ans. Plants like vegetables, fruits etc. and animals like sheep, goat, hen etc. are the various sources of food.
Q2. What are various sources of plant nutrients?
Ans. Rice, wheat, maize, pulses, spinach, fruits etc. are the various sources of plant nutrients.
Q3. Differentiate between farmyard manure and green manure?
Ans. Farmyard manure is an organic matter consisting of remnants of straw leaves, straw and cattle excreta. Green manure consists of leguminous crops like cluster beans, cowpea, horse gram etc.
Q4. What are the advantages of sea manures?
Ans.
Q5. Name two fertilizers supplying nitrogen, phosphate and potash.
Ans. Super phosphate, potash and NPK
Q6. Name any two irrigation systems in India?
Ans. Sprinkler system and drip system are two modern irrigation systems in India.
Q7. What are weeds? How do they affect crops?
Ans. Weeds are the undesirable plants that grow along with the crops. They compete with the crops for water, nutrients, space and light. Thus, they affect the growth of the crop.
Q8. Name any two insecticides.
Ans. Malathion and dimecron.
Q9. Name two harvest festivals.
Ans. Pongal and Baisakhi.
Q10. Name two main crops raised in India. Also mention their time of harvesting.
Ans. Paddy and Vegetables. They are harvested in October.
Q11. Name a machine which is used for harvesting.
Ans. Combine is used for harvesting.
Q12. Name the cereals grown in India.
Ans. Rice and Wheat.
Q13. Differentiate between agriculture and horticulture.
Ans. Agriculture is the study of science and art of production of plants while as horticulture is the science and art of growing fruits, vegetables, flowers and some ornamental plants.
Q14. Why is soil ploughed?
Ans. Soil is ploughed so that the roots of the young plants can penetrate it easily.
Q15. Name the methods of ploughing.
Ans. Ploughing can be done either by Ploughs driven by animals or by tractors.
Q16. Why do farmers raise seedlings in nursery?
Ans. Farmers raise seedlings in nursery so that they are not damaged so that to transfer them to the main field in right time.
WORKSHEET: 6.2
Q1. What is plant breeding?
Ans. The technique which involves the cross-breeding (hybridization) between two varieties of plants to obtain a new and better adapted variety is known as Plant Breeding.
Q2. How is plant breeding performed?
Ans. Plant breeding is performed by the process of cross-pollination. Anther of one plant is removed and pollen of another plant is dusted over the stigma of this plant and the process is repeated several times to yield an improved variety of stock.
Q3. What is crop rotation? What are its advantages?
Ans. The growing of crops in between two crops alternately to replenish the minerals of the soil is known as crop rotation. It increases the soil fertility and replenishes the minerals of the soil.
Q4. Name two leguminous crops.
Ans. Maize and groundnut.
Q5. What are the advantages of mixed cropping?
Ans. Mixed cropping helps the products and waste products of one crop to be utilized by another crop.
Q6. Name two crops which are grown together.
Ans. Groundnut and cotton.
Q7. Define field fallow.
Ans. To increase the humus of the soil and to promote the growth of micro-organisms to replenish the nutrients of the soil, the filed is left uncultivated for one season this is known as Field fallow.
Q8. Write the important features of a good storage structure.
Ans. Important features of good storage structure:
1.      It should be easy to clean.
2.      It should be waterproof.
3.      It should protect the grains against variation in temperature and humidity.
4.      It should be located at a convenient place so that transportation becomes easy.
5.      It should be well protected from rodents.
6.      It should be convenient for regular check-up of stored food materials.
7.      It should be convenient for the use of pesticides and also for the control of other microorganisms.
WORKSHEET: 6.3
Q1. What is livestock?
Ans. A farm where domesticated animals are kept, raised for use and profit.
Q2. Name any four poultry birds.
Ans. Hen, duck, turkey and geese
Q3. What is a broody hen?
Ans. An egg laying bird is called a broody hen.
Q4. Name any two breeds of:
(a)   Cows and (b) buffaloes
Ans. (a). Sahiwal and Sindhi
(b). Murrah and Jaffarabadi
Q5. Why is fishery flourishing in India on a large scale?
Ans. Fishery is flourishing in India on a large scale because it provides many useful things that are widely used in world and also brings more economy.
Q6. Name any four fish.
Ans. Catla, Labeo, Barbus and Tuna Cod.
Q7. Give any two uses of honey.
Ans. It helps in digestion of food. It increases immunity.
Q8. Give any two uses of wax.
Ans. It is used to make candles. It used in ointments and Vaseline
Q9. Give any four points for care of animals.
Ans. Proper care, proper food, proper shelter and protection.

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