NCERT Solutions for Class 12 Biology Chapter 9
| Class: | 12 |
| Subject: | Biology |
| Chapter 9: | Strategies for Enhancement in Food Production |
Class 12 Biology Chapter 9 Solutions in English
NCERT Solutions for Class 12 Biology Chapter 9 Strategies for Enhancement in Food Production is given on this page to free download in PDF format for session 2021-22. NCERT Books and NCERT Solutions 2021-22 for other subjects are also available to download. Join the discussion forum to ask your doubts.
Important Terms related to Chapter 9
1. Apiculture: Rearing of honeybees for the production of honey, bee wax, royal jelly and bee Venom.
2. Artificial insemination: Introduction of semen of good quality of male into the vagina of female by artificial means.
3. Explant: Any part of plant excised from its original location and used for tissue culture.
4. Germplasm Collection: The entire collection having all the diverse alleles for all the genes in a given crop.
5. Inbreeding: Inbreeding refers to the mating of more closely related individuals within the same breed for 4-6 generations.
6. Out-breeding: Out-breeding is the breeding of the unrelated animals, which may be between individuals of the same breed (but having no common ancestors), or between different breeds (cross breeding or different species (interspecific hybridisation).
6. Out crossing: Out-breeding is the breeding of the unrelated animals, which may be between individuals of the same breed (but having no common ancestors), or between different breeds (cross breeding or different species (inter-specific hybridisation)
7. Cross breeding: The practice of mating of animals of same breed but have no common ancestor on either side of pedigree upto 4-6 generations. A single outcross helps to overcome the inbreeding depression.
8. Totipotency: The ability or capacity of a cell or explant to give rise to a complete plant is called totipotency.
ABBREVIATIONS
ET: Embryo Transfer
IARI: Indian Agricultural Research Institute
IRRI: International Rice Research Institute
ICAR: Indian Council of Agriculture Research
MOET: Multiple Ovulation Embryo Transfer
NDRI: National Dairy Research Institute
Main steps in breeding a new genetic variety of crop
1. Germ-plasm collection or collection of variability
2. Evaluation and selection of parents
3. Cross breeding or hybridisation of selected parents.
4. Selection and testing of superior recombinants
5. Testing, release and commercialisation of new cultivars.
Know More about Plants
1. Plant breeding: Manipulation of plant species to create plants with desired qualities like high yield and disease resistance.
2. Blue Revolution: Increase in fish production due to utilisation of modern technology.
3. Mutation: Sudden inheritable change in the characters of an organism due to change in the sequence of bases in the gene(s).
Diseases of Plants
1. Viral: Tobacco mosaic, turnip mosaic
2. Bacterial: Black rot of crucifers, Blight of rice
3. Fungal: Rust of wheat, red rot of sugarcane, late blight of potato.
Important Questions on 12th Biology Chapter 9
What is meant by the term ‘breed’? What are the objectives of animal breeding?
A breed is a special variety of animals within a species. It is similar in most characters such as general appearance, size, configuration, and features with other members of the same species. Jersey and Brown Swiss are examples of foreign breeds of cattle. These two varieties of cattle have the ability to produce abundant quantities of milk. This milk is very nutritious with high protein content. Objectives of animal breeding To increase the yield of animals. To improve the desirable qualities of the animal produce. To produce disease-resistant varieties of animals.
Explain in brief the role of animal husbandry in human welfare.
Animal husbandry deals with the scientific management of livestock. It includes various aspects such as feeding, breeding, and control diseases to raise the population of animal livestock. Animal husbandry usually includes animals such as cattle, pig, sheep, poultry, and fish which are useful for humans in various ways. These animals are managed for the production of commercially important products such as milk, meat, wool, egg, honey, silk, etc. The increase in human population has increased the demand of these products. Hence, it is necessary to improve the management of livestock scientifically.
If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?
Dairy farm management deals with processes which aim at improving the quality and quantity of milk production. Milk production is primarily dependent on choosing improved cattle breeds, provision of proper feed for cattle, maintaining proper shelter facilities, and regular cleaning of cattle. Choosing improved cattle breeds is an important factor of cattle management. Hybrid cattle breeds are produced for improved productivity. Therefore, it is essential that hybrid cattle breeds should have a combination of various desirable genes such as high milk production and high resistance to diseases. Cattle should also be given healthy and nutritious food consisting of roughage, fibre concentrates, and high levels of proteins and other nutrients. Cattle’s should be housed in proper cattle-houses and should be kept in well ventilated roofs to prevent them from harsh weather conditions such as heat, cold, and rain. Regular baths and proper brushing should be ensured to control diseases. Also, time-to-time check-ups by a veterinary doctor for symptoms of various diseases should be undertaken.
What is apiculture? How is it important in our lives?
Apiculture is the practice of bee-keeping for the production of various products such as honey, bee’s wax, etc. Honey is a highly nutritious food source and is used as an indigenous system of medicines. It is useful in the treatment of many disorders such as cold, flu, and dysentery. Other commercial products obtained from honey bees include bee’s wax and bee pollen. Bee’s wax is used for making cosmetics, polishes, and is even used in several medicinal preparations. Therefore, to meet the increasing demand of honey, people have started practicing bee-keeping on a large scale. It has become an income generating activity for farmers since it requires a low investment and is labour intensive.
Discuss the role of fishery in enhancement of food production.
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 prawns crabs, oysters, lobsters, and octopus. Fisheries play an important role in the Indian economy. This is because a large part of the Indian population is dependent on fishes as a source of food, which is both cheap and high in animal protein. A Fishery is an employment generating industry especially for people staying in the coastal areas. Both fresh water fishes (such as Catla, Rohu, etc) and marine fishes (such as tuna, mackerel pomfret, etc.) are of high economic value.
What is the major advantage of producing plants by micropropagation?
Micropropagation is a method of producing new plants in a short duration using plant tissue culture. Some major advantages of micropropagation are as follows: Micropropagation helps in the propagation of a large number of plants in a short span of time. The plants produced are identical to the mother plant. It leads to the production of healthier plantlets, which exhibit better disease-resisting powers.
Which part of the plant is best suited for making virus-free plants and why?
Apical and axillary meristems of plants is used for making virus-free plants. In a diseased plant, only this region is not infected by the virus as compared to the rest of the plant region. Hence, the scientists remove axillary and apical meristems of the diseased plant and grow it in vitro to obtain a disease-free and healthy plant. Virus-free plants of banana, sugarcane, and potato have been obtained using this method by scientists.
Explain what is meant by biofortification.
Biofortification is a process of breeding crops with higher levels of vitamins, minerals, proteins, and fat content. This method is employed to improve public health. Breeding of crops with improved nutritional quality is undertaken to improve the content of proteins, oil, vitamins, minerals, and micro-nutrients in crops. It is also undertaken to upgrade the quality of oil and proteins. An example of this is a wheat variety known as Atlas 66, which has high protein content in comparison to the existing wheat. In addition, there are several other improved varieties of crop plants such as rice, carrots, spinach etc. which have more nutritious value and more nutrients than the existing varieties.
