Strategies for Enhancement in Food Production Class 12 Notes CBSE Biology Chapter 9 (Free PDF Download)

Section–A (1 Mark Questions)

1. What do you mean by animal husbandry?

Ans. Animal husbandry is the agricultural practice of breeding and raising livestock.

2. Which of the following are freshwater fishes? 

Catla, Common carp, Hilsa, Sardines, Mackerel, Pomfret?

Ans. Catla and Common carp are freshwater fishes while the others are predominantly marine.

3. Which is the best breeding method for animals that are below average in milk production?

Ans. Outcrossing is the best breeding method for animals that are below average in productivity in milk production, the growth rate in beef cattle, etc.

4. What is the full form of IARI?

Ans. IARI is an acronym for Indian Agricultural Research Institute. It is also known as the Pusa institute.

5. State any 2 objectives of biofortification.

Ans. Biofortification is undertaken with the objectives of improving – (i) Protein content and quality; (ii) Oil content and quality etc.

Section–B (2 Mark Questions)

6. What is the difference between apiculture and pisciculture?

Ans. Bee-keeping or apiculture is the maintenance of hives of honeybees for the production of honey. While pisciculture is rearing, catching and the management of fishes.

7. What is aquaculture? Name an animal that be multiplied by aquaculture.

Ans. Aquaculture is the culturing of plants and animals in freshwater. Examples – Shellfish, Shrimps, Oysters, etc.

8. What is Biofortification?  How many methods of biofortification are there?

Ans. The process of producing the new and improved quality of crops is called as the biofortification. This involves two important methods – Selective breeding and Genetic modification.

9. Why and how does beehive help in enhancing the yield?

Ans. When cultivated in the fields of Brassica, apple, pear and sunflower, beehives help to increase the pollination efficiency of flowering plants and hence improves the yield.

10. Why are plants obtained by protoplast culture called somatic hybrids?   

Ans. Plants obtained from protoplast culture are called somatic hybrids because they are created through the hybrid cells developed by the fusion of genetically different somatic cells.

PDF Summary - Class 12 Biology Strategies For Enhancement In Food Production Notes (Chapter 1)

Food is a substance that is very essential and provided to meet the body’s nutritional requirements. It contains proteins, carbohydrates, and fats. The enhancement of food production becomes a primary issue with the increase in population. Major efforts made to enhance the production of food and also to meet the requirements of the increasing population are plant breeding and animal husbandry.

9.1 What is Animal Husbandry? 

The technique which involves the agricultural practice of breeding and raising livestock is known as animal husbandry. It is the science of managing and caring for farm animals by human beings. It can also be defined as a practice of raising livestock for promoting desirable traits in animals for the sake of human welfare. It is estimated that more than 70 percent of the world’s livestock population is in India and China. 

Management of Farms and Farm Animals

1. Poultry Farm Management 

The use of domesticated fowl (birds) for food and egg is known as poultry farm management. It includes chickens and ducks and sometimes many turkeys and geese also. During poultry farm management few points should be kept under consideration on a priority basis. These are the arrangement of proper feed and water, maintaining hygiene and health care, proper and safe farm conditions, etc. Brooding temperature is also having a high degree of importance.

2. Dairy Farm Management 

The dairy farm management includes the management of animals for the milk and milk products. It includes the management that can improve the quality and yield of the milk. The quality of breeds on the farm determines the yield of the milk. Good breeds include those which have high yielding potential and resistance to disease. To achieve the good yielding potential, the cattle should be well looked at, their proper hygiene, food, and a disease-free environment should be provided. Along with this, proper storage and transport of milk should also be managed

9.2 Animal Breeding 

A significant aspect of animal husbandry deals with the breeding of animals. It aims to increase the yield of the animals and introduction of desirable traits into the animal. The word breed is defined as a group of animals that are related by features, size configuration, general appearance, etc. Breeding between the animals of the same breed is known as inbreeding and breeding between animals of the different breeds is known as outbreeding.

Inbreeding: 

A process that occurs between the members of closely related individuals within the same breed for about 4 to 6 generations is known as inbreeding. Here, first of all, males and females with superior traits are identified and then mated in pairs. Generally, it is the cow that carried the superior desired trait-like increased milk production and the superior male is the bull that can give superior progeny. Inbreeding results in increased homozygosity. This is harmful as it can lead to the expression of harmful recessive alleles. Superior traits can be eliminated. Continued inbreeding leads to inbreeding depression. Inbreeding depression is the loss of desired traits due to successive inbreeding. This affects both productivity and fertility. 

Outbreeding is the Breeding Among Unrelated Animals. 

For outbreeding such animals are chosen who do not have common ancestors for 5 to 6 generations. Cross-breeding involves breeding between a superior male of one breed and a superior female of another breed. The desired trait can be obtained through crossbreeding. The animals or the offspring obtained is known as a hybrid. From both the parents, the animal produce has both the desired trait. 

Difference between Inbreeding and Outbreeding

Interspecific hybridization involves mating between two unrelated animals. Two different related species can be used for interspecific hybridization. Progeny will get the desirable traits from both parents.

Artificial Insemination and Multiple Ovulation Embryo Transfer Technology

The experiment's artificial insemination is carried out for controlled breeding. Here the breeder collects the semen from the male parent and injects it into the female reproductive tract of the selected female. The semen can be stored or kept freeze to be used later and it can also be transported for injection into the required female animal. One of the disadvantages of artificial insemination is that the success rate is low. The multiple ovulation embryo transfer technology (MOET) came into the picture to improve the success rate of hybridization. This is hormonal-based technology where the female animal is injected with FSH-like hormone to induce follicular maturation and superovulation (more than one egg). Methods suitable using this method breeds of females that are high yielding for milk and bulls yielding high-quality meat (lean meat with less lipid) have been bred successfully. This helps to increase the number of organisms in a short time.

9.3. Beekeeping 

Apiculture or beekeeping is the maintenance of honey bees for honey and other products such as beeswax, propolis, pollen, and royal jelly. The products which are obtained from apiculture are having commercial significance. For example, beeswax is used in the cosmetic and medical industries. It is also used as a food additive and for cheese coating. It has been discovered recently that venom obtained from honey bees can be used for the treatment of AIDS. It has the potential to kill HIV. Common commercial species of honey bees are Apis dorsata (rock bee), Apis Indica (Indian bee), Apis florea (little bee), and Apis mellifera (Italian bee) that are used for apiculture. 

For successful beekeeping, the following points can be kept in mind: Proper knowledge about the nature and habits of bees. Selection of a method suitable location for the beehives. Ideally should be present sufficiently close to a foraging area. Catching and hiving of swarms. Maintenance of beehives during different seasons. Handling and collection of honey and beeswax. 

4. Aquaculture/Pisciculture 

Artificial rearing and management of catching, processing as well as selling fishes such as Rohu, Catla, and Hilsa, etc. are known as pisciculture. Due to more requirements of fishes’ different methods are employed to promote pisciculture. Aquaculture is defined as the methods of,pest-resistant pestresistant growing of aquatic animals and selling them for commercial purposes. There are two types of aquaculture- extensive aquaculture and intensive aquaculture. In the ocean, natural and man-made lakes, rivers, etc. the extensive aquaculture is done. Whereas intensive aquaculture exists in ponds and tanks. 

Plant Breeding

Plant breeding is the practice of selecting and breeding specific desired plant species to obtain desirable traits such as more yield, pest resistance, herbicide resistance, etc.

The main steps to be followed in breeding the new genetic crop are-

• Collection of variability is the basis of any breeding program. It is very much important to collect and preserve all the different wild varieties of species, and relatives of the cultivated species for effective exploitation of naturally available genes in the populations. The collection of plants or seeds that contains all the various alleles for all the genes found during a given crop is named a germplasm collection. 

• Parents with desirable characteristics are evaluated and selected.

• Among the selected parents the desired characters are now cross hybridized. This combines the characters genetically in the progeny. This is a timeconsuming and tedious process.

• Selection and testing of superior recombinants. Those plants are selected which were containing desired characters. The selection process is very crucial for the success of the breeding objective and it also requires very careful scientific evaluation of the progeny. 

• Testing, release, and commercialization of new cultivars. The evaluation of newly selected lines is done for their yield and other agronomic traits of quality, disease resistance, etc. By growing the new varieties and cultivars in the research fields, their testing is conducted out. Their performance under ideal fertilizer application, irrigation, and other crop management practices is then recorded and analyzed.

Plant Breeding for Disease Resistance 

Bacteria, fungi, and viruses affect different crop species. Approximately 20-30% of crops are lost due to different pathogens. The plant breeding technique is used to develop disease-resistant plants. To produce disease-resistant plants, it is essential to understand the causative agent of the disease and their mode of transmission.

Methods of Breeding for Disease Resistance 

Breeding can occur through a conventional method such as hybridization and selection. It includes steps such as screening germplasm for resistant genes, hybridization of selected parents, selection and evaluation of the hybrids, testing and release of new varieties. But there are certain disadvantages in the conventional method in terms of few known disease-resistant genes.

Mutational Breeding 

It is one of the methods of plant breeding that modifies the base sequence/nucleotide sequence of a gene to obtain new traits other than those observed in parents. These mutations or changes are introduced in plants either by chemicals or radiations such as X-rays.

“For example, A variety named Mung bean is prepared by the process of mutation and this variety of plants is also resistant to yellow mosaic virus”. Breeding to obtain insect or pest-resistant variety.

Based on different strategies insect or pest-resistant plants are produced. The strategies are-

• They are modified in such a manner that they become tasteless. That is why animals avoid eating these plants. 

• They also produce some toxins that can paralyze the infected insect. 

• They are modified morphologically such as hairier, pointed leaves, odor, methods suitable, etc.

Plant breeding has helped to develop several useful and important varieties of certain crop plants such as tobacco, potato, okra.

Plant Breeding for Improved Food Quality 

Plant breeding is important for improving the quality of food as well as to fulfill the nutritional requirement of food. Diets, especially plant-based diets that lack essential micronutrients increase the chances of diseases, reduce life span and reduce mental abilities. The main objective of plant breeding for the improvement of food quality is to improve the nutrient content, protein content, oil content, vitamin, and mineral content also. 

Biofortification

Biofortification is an innovative technology through which the nutritional quality of food is improved with the help of agronomic practices, conventional plant breeding, and modern biotechnology. In the year 2000, maize hybrids were developed that bears double the number of amino acids, lysine, and tryptophan, as compared to existing maize hybrids. A variety of wheat which is having a high protein content e.g. A variety named Atlas 66, has been used as a donor for improving cultivated wheat. Nowadays it’s become easy to develop an ironfortified rice variety that contains over five times the utmost amount of iron as in commonly consumed varieties. The Indian Agricultural Research Institute, New Delhi has developed different varieties of vegetable crops which were rich in nutrient contents such as vitamins and minerals, e.g., vitamin A enriched carrots, spinach, pumpkin; bitter gourd, bathua, mustard, tomato with enriched vitamin C; spinach and bathua with enriched iron and calcium and proteinenriched beans – broad, lablab, French and garden peas.

Single-Cell Protein (SCP) 

The single-cell protein is an alternative source of protein available for both animals and humans. Edible unicellular microbes can also be defined as singlecell proteins. One of the richest sources of protein, minerals, fats, carbohydrates, and vitamins is spirulina. This is also one of the methods of reducing the environmental pollution.

Tissue Culture 

Tissue culture is defined as the capability of developing a whole plant from the part of the plant. This capacity to form a whole organism/plant is known as totipotency. The nutrient medium and growth regulators such as auxins, cytokinins are necessary for tissue culture. This method of producing a large number of plants in a very short period is known as micropropagation. It will produce genetically identical plants known as some clones. Meristem (cells that have the capability of repeated cell division) can be used to grow virus-resistant plants such as bananas, sugarcane, etc.