Class 12 Biology

Enhancement in Food Production

NCERT Exercise

Question 1: Explain in brief the role of animal husbandry in human welfare.

Answer: Animals have been bred and reared by humans since time immemorial. Animals are important for human welfare because they are the source of milk, meat and eggs for us. Moreover, honey which is another nutritious food comes from animal. Milk, dairy products, meat and egg form major part of our food basket. This shows the importance of animal husbandry in human welfare.

Question 2: If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?

Answer: I will take following steps to improve the quality and quantity of milk production:

Question 3: What is meant by the term ‘breed’? What are the objectives of animal breeding?

Answer: A group of animals related by descent and similar in most characters are said to belong to a breed. Objectives of animal breeding are to incorporate desirable characteristics in animals. Some examples of these characteristics are; high milk yield, high yield of meat and eggs. Set of traits would depend on particular need while breeding a particular type of animal.

Question 4: Name the methods employed in animal breeding. According to you which of the methods is best? Why?

Answer: Following are the methods of animal breeding.

Out of the above methods, cross-breeding is the best method because it allows one to combine desirable characteristics from two different breeds. This gives better scope for developing better animal from commercial perspective.

Question 5: What is apiculture? How is it important in our lives?

Answer: Maintenance of hives of honeybees for production of honey is called bee-keeping or apiculture. Honey and bees-wax are obtained from honey bees. Honey is a nutritious food which is widely used as food additive. Honey also has many medicinal properties. Bees-wax is used for making candles and cosmetics, and also some medicines.

Question 6: Discuss the role of fishery in enhancement of food production.

Answer: Fish is an important source of protein for a vast section of population. Fishery helps in improving the availability of protein rich food for us. Thus, it helps in enhancement of food production.

Question 7: Briefly describe various steps involved in plant breeding.

Answer: The main steps in breeding a new genetic variety of a crop are as follows:

Question 8: Explain what is meant by biofortification.

Answer: Breeding crops with higher levels of vitamins and minerals or other nutrients is called biofortification. This method has been successfully applied to produce iron-rich rice, protein rich maize. Many vegetables and fruits fortified with vitamins and minerals have been produced by this method.

Question 9: Which part of the plant is best suited for making virus-free plants and why?

Answer: The meristem does not get infected with pathogens. Hence, meristem is bets suited for making virus-free plants.

Question 10: What is the major advantage of producing plants by micropropagation?

Answer: Micropropagation helps in producing a large number of saplings at a small scale. Micropropagation is still at experimental stage. A day may come when it will help in production of plants on commercial scale. This will help in solving the problem of scarcity of land for growing plants.

Question 11: Find out what the various components of the medium used for propagation of an explant in vitro are?

Answer: Different components of the medium used for propagation of an explants in vitro are; carbon source such as sucrose and also inorganic salts, vitamins, amino acids and growth regulators like auxins, cytokinins, etc.

Question 12: Name any five hybrid varieties of crop plants which have been developed in India.

Answer: Himgiri(Wheat), Pusa swarnim (Brassica), Pusa Shubhra (cauliflower), Pusa Komal (cowpea) and Pusa Sadabahar (chilli)