NCERT Solutions for Class 12 Biology Chapter 9 - Strategies for Enhancement in Food Production

Question 1:

Explain in brief the role of animal husbandry in human welfare.

Answer:

Animal husbandry is the agricultural practice of breeding and raising livestock. Due to a drastic increase in world population, animal husbandry has become a major necessity.
1. Animal husbandry has a major role to increase food production.
2. It provides various animal products like milk, eggs, meat, wool, silk, honey etc.
3. It caters to the increasing food demand by the people and, on the commercial aspect, also fetches a lot of foreign exchange.
4. Demand for aquatic foods especially fish and fish products has also been met by animal husbandry practice, thus animal
husbandry has a multi-fold role to play 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:

Dairying is the management of animals for milk and its products for human consumption. In order to set up and successfully manage a dairy farm, the following aspects should be taken care of:
1. Selection of animals capable of high yielding potential and resisting diseases.
2. Proper housing of the cattle.
3. Maintenance of hygienic conditions in the dairy farm.
4. Adequate water supply to cattle.
5. Good quality food for cattle with special emphasis on quality and quantity of fodder.
6. Efficient milking, storage and transport of milk.
7. Record keeping of the farm.
8. Regular inspections of the farm.
9. Regular visits by health experts and veterinary doctor to the farm.

Question 3:

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

Answer:

Breed. A group of animals related by descent and similar in most characters like general appearance, features, size, configuration etc. are said to belong to a breed. The objectives of animal breeding are:
(a) Increasing the yield of animals.
(b) Improving the desirable qualities of the produce.
(c) To combine good qualities of two different breeds by cross breeding.

Question 4:

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

Answer:

The methods employed in animal breeding are:
A. Natural methods. These are as follows:
(a) Inbreeding.
(b) Outbreeding which may be done by:
(i) Outcrossing
(ii) Cross breeding
(iii) Interspecific hybridization
B. Artificial methods. They include super ovulation and embryo transplantation, and multiple ovulation embryo transfer technology (MOET.)
Out of these methods, cross breeding is the best method of animal breeding because it is breeding between the superior males of another superior female breed. It allows the desirable qualities of two different breeds to be combined and give the best quality of yield.

Question 5:

What is apiculture? How is it important in our lives?

Answer:

Apiculture is the maintenance of hives of honeybees for commercial purposes. It is also called Bee-keeping. Apiculture is very important is our lives because it produces products of high economic and nutritive value:
(a) The main product of bee keeping is honey which is a highly nutritious edible product. It replaces the use of sugar in many industries.
(b) Honey is used as a part of many indigenous medicines.
(c) Another product called beeswax is also produced which is used in cosmetic and polish industry.
(d) Honey bees are chief pollinating agents so help in improving the plant yield.

Question 6:

Discuss the role of fishery in enhancement of food production.

Answer:

Fishery as an industry has an important place in the Indian economy and plays a major role in catering to the increasing needs of food production.
Through blue revolution, the fish production has increased.
1. Fish is used as an edible substance and is of high protein value.
2. Fish products are also of great use and other aquatic animals like prawn, crab, lobster, edible oyster are also eaten as food.

Question 7:

Briefly describe the various steps involved in plant breeding.

Answer:

The various steps involved in plant breeding are discussed below:
1. Collection of variability. The entire collection (of plants / seeds) having all the diverse alleles for all genes in a given crop is called germplasm collection.
2. Evaluation and Selection of parents. The germplasm is evaluated to identify plants with desirable combination of useful characters. The selected plants are multiplied and used in the process of hybridization. Pure lines are created wherever desirable and possible.
3. Cross hybridization among the selected parents. Cross hybridizing the two parents to produce hybrids that genetically combine the desired characters in one plant.
4. Selection and testing of superior recombinants. This step consists of selecting, among the progeny of the hybrids, those plants that have the desired character combination. The selection process is crucial to the success of the breeding objective and requires careful scientific evaluation of the progeny. This step yields plants that are superior to both of the parents (very often more than one superior progeny plant may become available).
5. Testing, release, and commercialization of new cultivars. The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance etc. This evaluation is done by growing these in the research fields and recording their performance under ideal fertiliser application, irrigation and other crop management practices. The evaluation in research fields is followed by testing the materials in farmers fields, for at least three growing seasons, at several locations in the country, representing all the agroclimatic zones where the crop is usually grown.
The material is evaluated in comparison to the best available local crop cultivar – a check or reference cultivar.

Question 8:

What is importance of biofortification?

Answer:

The method of breeding crops with higher levels of vitamins and minerals or higher protein and healthier fats is called biofortification. It is one of the most important method for improving public health. During recent past, many varieties of crop plants such as rice, carrots, spinach, pumpkin, bathua have been developed which possess several times more nutritive value and vitamins as compared to existing varieties.

Question 9:

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

Answer:

The apical or axilliary meristems are best suited for making virus-free plants because they are generally free from virus.

Question 10:

What is the major advantage of producing plants by micropropagation?

Answer:

Significance of Micropropagation. This method is applied for rapid multiplication of valuable plant material for agriculture, horticulture and forestry.
It may enhance:
(a) Multiple shootlet production. As in micropropagating potato, cardamom, orchids, banana, begonias, Chrysanthemum, etc.
(b) Somatic embryogenesis. Somatic embryos or embryoids may be developed. The advantage of embryoids is that it forms a complete plant with a tap root system as in carrot, celery and alfalfa.

Question 11:

What are the various components of the medium used for propagation of an explant in vitro?

Answer:

The medium used for growth and development of explant in tissue culture technique is called culture medium. Standard culture medium contains water, agar-agar, sucrose, inorganic salts, certain vitamins, amino acids and growth regulators. (i.e. 2, 4-D and B.A.P.)

Question 12:

Name any five varieties of crop plants which have been developed in India.

Answer:

(a) Himgiri variety of Wheat. (b) Pusa Swarnim variety of Brassica.
(c) Pusa Shubhra variety of Cauliflower.
(d) Pusa Komal variety of Cowpea.
(e) Pusa Sadabahar variety of Chili.