NCERT Solutions for Class 12 Biology Chapter 9: Strategies for Enhancement in Food Production
NCERT Solutions for Class 12 Biology Chapter 9 Free PDF Download
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1. Explain in brief the role of animal husbandry in human welfare.
Ans. Animal husbandry deals with caring, feeding and management of livestock like buffaloes, cows, camels, fishes, birds, cattles, etc.
Role of animal husbandry in human welfare:
(i) Animals provide products which are used as food by human like meat, honey, eggs, etc.
(ii) There are some other substances obtained by animals which are beneficial to human like wool, silk, leather, bee waxes, etc.
2. If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?
Ans. Some of the measures to be followed for proper management of dairy farm are :
(i) Selection of good breeds having high milk yielding potential and resistance to disease.
(ii) The shed under which the cattle are kept should be well ventilated with an adequate water supply for drinking as well as for washing. Shed should have pucca floor and proper drainage channel.
(iii) The feed of the animals should be a balanced diet with right proportions of carbohydrates, fats, proteins, and roughage and it should be given timely in good quantity.
(iv) Cleanliness and hygiene comes first for maintaining the livestock’s health and productivity. So, washing cattle and taking precautionary measures while milking are a must.
(v) Inspection, keeping records of the activities and consulting a veterinary doctor for regular checkups of the livestock should be undertaken.
3. What is meant by the term ‘breed’? What are the objectives of animal breeding?
Ans. A group of animals which are related by descent to each other and similar in most characteristics like appearance, size, features etc. are said to belong to a breed.
The objectives of animal breeding are:
(i) Increasing the yield and high disease resistance in animals.
(ii) Improving the quality of desired product.
4. Name the methods employed in animal breeding. According to you which of the methods is best? Why?
Ans. There are two methods employed in animal breeding:
(i) Natural method: It is of three types.
(a) Out-crossing
(b) Cross-breeding
(c) Interspecific hybridization
(ii) Artificial method: It is of two types.
(a) Artificial insemination
(b) Multiple Ovulation Embryo Technology (MOET).
From the above method Multiple Ovulation Embryo Technology (MOET) is the best method because through MOET, many successful results has been obtained like increasing hard size in a short time, development of high yielding cows and high-quality meat yielding bulls have been developed.
5. What is apiculture? How is it important in our lives?
Ans.Apiculture: Apiculture is the practice of bee-keeping for the production of various products such as honey-bee’s wax, etc.
Importance of apiculture: The importance of apiculture in our lives are as follow:
(i) Honey is a highly nutritious food source and is used as an indigenous system of medicines.
(ii) Other commercial products obtained from honeybees include bee’s wax and bee pollen. Bee’s wax is used for making cosmetics, polishes and is even used in several medicinal preparations.
6. Discuss the role of fishery in the enhancement of food production.
Ans. Fishery is an industry which deals with catching, processing and marketing of fishes and other aquatic animals that have a high economic value.
Some commercially important aquatic animals are prawn, crabs, oysters, lobsters and octopus. Fisheries play an important role as meat of fishes is rich source of collagen protein, which is beneficial for skin and other useful substances like polyunsaturated fatty acids (PUFA).
7. Briefly describe various steps involved in plant breeding.
Ans.The various steps involved in plant Breeding are as follows:
Step 1: Collection of genetic variability: In this, the different types of genes from wild varieties are collected to maintain genetic diversity.
Step 2: Evaluation and selection of parents: It this, evaluation of the desired gene from germplasm for breeding is done.
Step 3: Cross-hybridization between selected parents: In this, the plants with the desired character crossed to produce hybrid.
Step 4: Selection and testing of superior hybrid: The progeny of hybrid of having desired characters are selected through scientific methods.
Step 5: Testing, release and commercialization of new cultivates: The selected progenies are evaluated for characters such as yields, resistance to disease, etc. After selecting and testing of seeds, they are distributed to market.
8. Explain what is meant by biofortification.
Ans. Biofortification is method of breeding crops with higher levels of vitamins and minerals, or higher proteins and healthier fats in view to improve public health. E.g., iron-fortified rice containing five times more iron than other varieties, wheat variety, Atlas 66 having high protein content, maize varieties having high lysine and tryptophan are produced.
9. Which part of the plant is best suited for making virus-free plants and why?
Ans. The meristem is the plant part which is best suited for making virus free plants. This because when a plant is infected by virus, the meristem remains virus free. This meristem can be removed and grown in-vitro to obtain virus free plant.
10. What is the major advantage of producing plants by micropropogation?
Ans. The major advantages of plants producing by micropropogation are as follows:
(i) It helps in the propagation of large number of plants in a short span of time.
(ii) The plants produced are identical to the mother plant.
(iii) It leads to produce healthier plants, which have better disease resistance.
(iv) Plants can be obtained through out the year.
(v) Sterile plant can be multiply by micropropagative.
11. Find out what the various components of the medium used for propagation of an explant in vitro are.
Ans. The major components of the medium for in-vitro propagation are:
(i) Water
(ii) Agar-agar
(iii) Sucrose
(iv) Inorganic salts
(v) Vitamins
(vi) Amino acids
(vii) Growth hormones like
Auxin, Cytokinins.
12. Name any five hybrid varieties of crop plants which have been developed in India.
Ans.The five hybrid varieties of crop plants which have been developed in India are:
(i) Wheat – Sonalika
(ii) Rice – Jaya and Ratna
(iii) Cauliflower – Pusa shubra
(iv) Cowpea – Pusa komal
(v) Mustard – Pusa swamim.
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