Topics and Subtopics in NCERT Solutions for Class 12 Biology Chapter 9 Strategies for Enhancement in Food Production:

QUESTIONS FROM TEXTBOOK SOLVED

1. Explain in brief the role of animal husbandry in human welfare.
Ans: Animal husbandry deals with the caring, feeding and management of domesticated animals. It includes poultry, farming and fisheries.
These animals are very useful for human beings because
(i) they provide products which are used as food like meat, milk, eggs, honey, etc.
(ii) there are some other substances obtained from animals which are beneficial to human beings like wool, silk, leather, bees wax etc.

2. If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?
Ans: To improve the quality & quantity of milk production, one should take care of the following points:
(i) Proper feeding of the cattle with good quality of food.
(ii) Clean and hygienic environment for cattles.
(iii) Proper medication.
(iv) Veterinary supervision.
(v) Selection of good breeds having high yielding capacity combined with resistance to disease.
(vi) Quality of breed.

3. What is meant by the term ‘breed’ ? What are the objectives of animal breeding?
Ans: A group of animals related by descent and similar in most characters like general appearance, features, size, configuration etc. is called a breed.
The main objectives of animal breeding are:

• To produce high yielding varieties of animals like high milk producing cattle, more egg producing varieties of chicken, more wool bearing sheep varieties etc.
• To produce drought varieties for doing work like cattle, etc.
• To produce disease resistant varieties of the livestocks.

4. Name the methods employed in animal breeding. According to you which of the methods is best? Why?
Ans: Methods employed in animal breeding are
(i) Inbreeding
(ii) Out-breeding
(iii) Cross-breeding
(iv) Interspecific hybridization
(v) Artificial insemination
(vi) Multiple Ovulation Embryo Transfer Cross breeding is the best method as it results in the development of superior traits of both the breeds and the progeny produced are fertile and there is no inbreeding depression.

5. What is apiculture? How is it important in our lives?
Ans: Apiculture is the rearing and breeding of honeybees for the production of honey .
It is important in our live as honeybees provide honey, which is a highly nutritive substance and beeswax is used in many industries. Honeybees also pollinate flowers of some very important plants like sunflower, apple, pear.

6. Discuss the role of fishery in enhancement of food production.
Ans: Fishery is an industry which is concerned with the catching, processing or selling of fish. The role of fishery in enhancement of food production is as follows :

1. The fish flesh is an excellent source of protein. It has very little fat, carries a good amount of minerals and vitamins A and D and is rich in iodine.
2. Fish oil extracted from the liver of the sharks, sawfishes, etc., has medicinal value.
3. Shagreen, the skin of sharks and rays are used in polishing the wood and other materials.
4. The silvery bony scales of cyprimids are used in the manufacture of artificial pearls.
5. Fish glue is a sticky product obtained from the skin of cod and is used as gum.
6. Fish waste after the extraction of oil is used as fertilizer.
7. The fishing industry has brought a lot of income to the farmers in particular and the country in general because of “Blue Revolution” (fish production) in the same lines as ‘Green Revolution’ (for producing enough food for all).

7. Briefly describe various steps involved in plant breeding.
Ans: Plant breeding is a purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better yields and are disease resistant. The given flow chart shows various steps involved in plant breeding.

8. Explain what is meant by biofortification.
Ans: Enhancement of nutritional quality of a crop by improving the content and quality of protein, fats, vitamins, minerals and micronutrient is called biofortification. It helps to improve public health.

9. Which part of the plant is best suited for making virus-free plants and why?
Ans: The apical and axillary meristems of plants are the best parts of the plant to make virus-free plants. This is because rate of division of meristematic cell is higher than rate of multiplication of virus and viruses are unable to invade newly formed meristematic cells. Hence, meristematic cells are free of virus although the whole plant is infected with virus. With the use of meristem, a healthy plant can be recovered from the diseased plant through micropropagation method.

10. What is the major advantage of producing plants by micro propagation?
Ans: It is faster method of producing a large number of plants. Plants formed by micro propagation are identical.

11. Find out the various components of the medium 12.used for propagation of an explant in vitro are ?
Ans: The various components of the medium used for propagation of an explant in vitro are
-Sucrose (source of energy & carbon)
-Inorganic salts
-Vitamins
-Growth regulators (auxins and cytokinins)

12. Name any five hybrid varieties of crop plants which have been developed in India.
Ans: Sonalika (wheat)
Himgiri (wheat)
Pusa Swamim (mustard)
PusaSem2 (bean)
Pusa Sawani (lady’s finger)