NEET Biology Class 12 Strategies For Enhancement In Food Production Notes

Strategies For Enhancement In Food Production

Animal Husbandry

• It is the scientific agricultural practice of breeding and raising livestock.
• It deals with the care & breeding of livestock (buffaloes,
• cows, pigs, horses, cattle, sheep, camels, goats etc.)
  poultry farming and fisheries.
• More than 70% of the world’s livestock population is in
• India & China. However, the contribution to the world farm produce is only 25%, i.e., the productivity per unit is very low.
• Hence new technologies should be applied to achieve improvement in quality and productivity.

Read And Learn More: NEET Biology Class 12 Notes

Management of Farms And Farm Animals

1. Dairy Farm Management (Dairying):

• It is the management of animals to increase the yield and quality of milk and its products.
• Milk yield depends on the quality of breeds on the farm.
• It is important to select good breeds that have high-yielding potential and resistance to diseases.

Ways for the yield potential:

• Look after the cattle (housing well, giving adequate water, and maintaining disease-free).
• Feeding of cattle in a scientific manner – emphasis on the quality and quantity of fodder.
• Stringent cleanliness and hygiene of cattle & handlers while milking, storage, and transport of the milk.
• Nowadays, these processes have been mechanized. It reduces the chance of direct contact of the produce with the handler.
• Tensure these stringent measures there should be
• Regular inspections identify and rectify problems.
• Regular visits by a veterinary doctor.

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2. Poultry Farm Management:

Poultry is a domesticated bird used for food or eggs. Examples are chicken, ducks, turkey, and geese.

Components of poultry farm management:

• Selection of disease-free and suitable breeds.
• Proper and safe farm conditions.
• Proper feed and water.
• Hygiene and health care.

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Animal Breeding:

• A breed is a group of animals related by descent and similar general appearance, features, size, etc.
• Breeding is the modification of the genotype of an organism to make that organism more useful to humans. Example,  Jersy
• (improved cattle breed), and Leghorn (improved chicken breed).
• Animal breeding aims at increasing the yield of animals and improving the desirable qualities of the produce.

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Breeding is 2 types:

1. Inbreeding and
2. Out-breeding

NEET Biology Class 12 Strategies for Enhancement in Food Production Notes

1. Inbreeding:

• It is the mating of more closely related individuals within the
• same breed for 4-6 generations. This strategy is as follows:
• Identify and mate superior males & females of the same breed
• Evaluate the progeny obtained and identify superior males and females among them for further mating.
• In cattle, a superior female produces more milk per lactation.
• A superior male (bull) gives rise to superior progeny.

Inbreeding Advantages:

• It increases homozygosity to a pure-line animal. It exposes harmful recessive genes that are eliminated by selection.
• It helps in the accumulation of superior genes and the elimination of less desirable genes. This increases the productivity of the inbred population.
• Continued inbreeding, especially close inbreeding, may reduce fertility and productivity. This is called inbreeding depression.
• To solve this problem, selected animals should be mated with unrelated superior animals of the same breed.

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2. Out-breeding:

It is the breeding of the unrelated animals. It includes outcrossing, cross-breeding, and inter-specific hybridization.

1. Out-crossing
2. Cross – Breeding:
   • This is the mating of animals within the same breed, but having common ancestors on either side of their pedigree up to generations.
   • The offspring of such a mating is known as out-cross.
   • It is the best method for animals having low productivity in milk production, growth rate in beef cattle, etc.
   • It helps overcome inbreeding depression.
   • In this method, superior males of one breed are mated with superior females of another breed.
   • The desirable qualities of 2 different breeds are combined.
   • The progeny hybrid animals may be used for commercial production or may be subjected to inbreeding and selection to develop new stable superior breeds.
   • For example, Hisardale (sheep) developed in Punjab by crossing
   • Bikaneri ewes and Marinrams.

Strategies for Enhancement in Food Production NEET Notes

1. Interspecific hybridization:
   • It is the mating of males and females of two different species.
   • In some cases, the progeny may combine desirable features of both parents and may be of considerable economic value. For example, Mule (male ass X female horse).

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Controlled Breeding Experiments

1. Artificial insemination:

• The semen collected from a male parent is injected into the reproductive tract of the selected female by the breeder.
• Semen is used immediately or is frozen and used later.
• Frozen semen can also be transported.
• The success rate of crossing mature male & female animals is low even though artificial insemination is carried out.

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2. Multiple Ovulation EmbryTransfer Technology (MOET)”

It is a program for herd improvement. It improves 47 chances of successful production of hybrids.

• In this, a cow is administered hormones, with FSH-like activity, to induce follicular maturation and superovulation (production of 6-8 eggs per cycle instead of one egg).
• The animal is either mated with an elite bull or artificially inseminated. Fertilized eggs at 8–32 cell stages are recovered and transferred to surrogate mothers.
• MOET has been demonstrated for cattle, sheep, rabbits, buffaloes, mares, etc.
• High milk-yielding breeds of females and high-quality (lean meat with less lipid) meat-yielding bulls have been bred successfully to increase herd size in a short time.

Class 12 Biology Notes For Neet

Bee-Keeping (Apiculture)

• It is the maintenance of hives of honeybees to produce honey and beeswax.
• The most common species that can be reared is Apis indica.
• Honey is a food of high nutritive and medicinal value.
• Beeswax is used in the preparation of cosmetics, polishes, etc.
• Apiculture can be practiced in an area having bee pastures of some wild shrubs, fruit orchards, and cultivated crops.
• Important points for successful bee-keeping:
  • Knowledge of the nature and habits of bees.
  • Selection of suitable location for keeping beehives.
  • Catching and hiving of swarms (group of bees).
  • Management of beehives during different seasons
  • Handling and collection of honey and of beeswax.
  • Bees are the pollinators of crop species such as sunflower,
  • Brassica, apple, and pear.
• Keeping beehives in crop fields during the flowering period increases pollination. It improves crop and honey yield.

Strategies For Enhancement In Food Production Notes

Fisheries

The fishery is an industry of catching, processing, or selling fish, shellfish, or other aquatic animals (prawn, crab, lobster, edible oyster, etc.).

• Freshwater fishes: Catla, Rohu, common carp, etc.
• Marine fishes: Hilsa, Sardines, Mackerel, Pomfrets etc.
• Fisheries provide income and employment to millions of fishermen and farmers.
• Aquaculture: Aquaculture (farming of aquatic organisms) & pisciculture (farming of fishes) are the techniques to increase the production of aquatic plants and animals. Blue
• Revolution: The development and flourishing of the fishery industry.

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Plant Breeding

It is the manipulation of plant species to create desired plant types suitable for better cultivation, better yields, and disease resistance.

Green Revolution: The development and flourishing of agriculture. It was dependent on plant breeding.

Class 12 Strategies For Enhancement In Food Production

Classical plant breeding:

• Classical plant breeding involves the hybridization of pure lines and artificial selection to produce desirable traits.
• Now molecular genetic tools are used for plant breeding.

Desirable traits that breeders have tried to incorporate:

• Increased crop yield.
• Improved quality.
• Increased tolerance of to environmental stresses (salinity, extreme temperatures & drought), and resistance to pathogens.
• Increased tolerance of insect pests.

NEET Biology Strategies for Enhancement in Food Production Important Notes

Steps of Plant Breeding

1. Collection of genetic variability:

• In wild relatives of many crops, pre-existing genetic
• variability is available.
• Collection and preservation of wild varieties, species, and relatives of the cultivated species is a prerequisite for effective exploitation of natural genes.
• The entire collection of plants/seeds having all the alleles for all genes in a given crop is called germplasm collection.

2. Evaluation and selection of parents:

• The germplasm is evaluated for identifying plants with desirable characteristics.
• Selected plants are multiplied and used for hybridization.
• Pure lines are created wherever desirable and possible.

Class 12 Strategies For Enhancement In Food Production

3. Cross-hybridization of the selected parents:

• It is the process in which desired characters are genetically combined from 2 different parents to produce a hybrid plant
• For example, the high protein quality of one parent is combined with disease resistance from another parent.

Cross-hybridization Limitations:

• Very time-consuming and tedious process.
• Hybrids may not combine the desirable characteristics.
• Usually, only hundreds ta thousand crosses show the desirable combination.

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4. Selection & testing of superior recombinants

• It is crucial to the success of the breeding objective and requires careful scientific evaluation of the progeny.
• It yields plants that are superior to both parents.
• These are self-pollinated for several generations till they reach a state of uniformity (homozygosity), that the characters will not segregate in the progeny.

5. Testing, release & commercialization:

• The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance, etc.
• This is done by growing them in the research fields and recording their performance under ideal fertilizer application irrigation and other crop management practices.
• The evaluation is followed by testing the materials in farmers’ fields, for at least 3 growing seasons at several
• Locations in the country, representing all the agro-climatic zones. The material is evaluated in comparison to the best available local crop cultivar (a check or reference cultivar).

Class 12 Strategies For Enhancement In Food Production

Wheat and Rice:

• In India, food production has increased by the development of high-yielding varieties of wheat and rice in the mid-
• 1960s (Green Revolution).
• From 1960 to 2000, wheat production increased from 11 million tons to t75 million tons. The rice production increased from 35 million tons to t89.5 million tons.
• Nobel laureate Norman E. Borlaug (International Centre for Wheat & Maize Improvement, Mexico) developed semi-dwarf wheat.
• In 1963, high-yielding and disease-resistant wheat varieties like Sonalika & Kalyan Sona were introduced in India.
• Semi-dwarf rice varieties were derived from IR-8, (developed at International Rice Research Institute (IRRI),
• Philippines) and Taichung Native-1 (from Taiwan). Later better-yielding semi dwarf varieties Jaya and Ratna were developed in India.

Sugar cane:

Saccharum barberi (grown in north India, but with poor sugar content & yield) was crossed with Saccharum officinarum (tropical canes in south India, thicker stems and higher sugar content but not grow well in north India) and got a hybrid sugar cane having desirable qualities like high yield, thick stems, high sugar, and ability grow in north India.

Strategies for Enhancement in Food Production Class 12 NEET Key Concepts and Summary

Millets:

Class 12 Strategies For Enhancement In Food Production

Hybrid maize, jowar & bajra developed in India. It includes high-yielding varieties resistant to water stress.

Plant Breeding for Disease Resistance

• It enhances food production and helps to reduce the use of fungicides and bactericides.
• Resistance of the host plant is the genetic ability to prevent the pathogens from disease.

Some plant diseases:

• Fungal: Rusts. for example, brown rust of wheat, red rot of sugarcane and late blight of potato.
• Bacterial: Black rot of crucifers.
• Viral: Tobaccmosaic, turnip mosaic, etc.

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Methods of breeding for disease resistance

1. Conventional breeding: The steps are:

• Screening germplasm for resistance sources.
• Hybridisation of selected parents.
• Selection and evaluation of the hybrids.
• Testing and release of new varieties.

Some crop varieties bred by Conventional method:

NEET Biology Class 12 Chapter Strategies for Enhancement in Food Production Detailed Notes

Conventional breeding is constrained by the availability of a limited number of disease-resistance genes.

Strategies For Enhancement In Food Production Class 12

2. Mutation breeding:

• Mutation (sudden genetic change) can create new desirable characteristics not found in the parental type.
• Mutation breeding is the breeding by mutation using chemicals or radiations (e.g. gamma rays) to produce plants with desirable characteristics. Such plants are selected and multiplied directly or used as a source in breeding.
• For example, In mung bean, resistance to yellow mosaic virus and
• powdery mildew was induced by mutations
• Resistant genes from wild species have been introduced in the high-yielding cultivated varieties. example, In Bhindi (Abelmoschus esculentus), resistance to yellow mosaic virus was transferred from a wild species. It resulted in a new variety of A. esculentus called Parbhani kranti.
• Transfer of resistance genes is achieved by sexual hybridization between the target and the source plant.

Plant Breeding for Developing Resistance to Insect Pests

Insect resistance in host crop plants may be due to morphological, biochemical, or physiological characteristics.

• Hairy leaves: Eaxmple, resistance tjassids in cotton, and cereal leaf beetle in wheat.
• Solid stems in wheat lead to non-preference by the stem sawfly.
• Smooth-leaved and Nectar-less cotton varieties do not attract bollworms.
• High aspartic acid, low nitrogen, and sugar content in maize lead to resistance to maize stem borers.

Sources of resistance genes for breeding are cultivated varieties, germplasm collections of crops, or wild relatives.

Strategies For Enhancement In Food Production Class 12

Some crop varieties bred for insect pest resistance:

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Plant Breeding for Improved Food Quality

• More than 840 million people in the world do not have adequate food. 3 billion people suffer from micronutrients, protein, and vitamin deficiencies (‘hidden hunger’).
• Breeding crops with higher levels of nutrients is called
• Biofortification. It helps to improve public health.

Strategies For Enhancement In Food Production Class 12

Objectives of breeding for improved nutritional quality:

• To improve Protein content and quality.
• To improve Oil content and quality.
• To improve Vitamin content.
• To improve Micronutrient and mineral content.

Examples of hybrids with improved nutritional quality:

• Maize hybrids have twice the amount of amino acids, lysine & tryptophan compared to existing maize hybrids.
• The wheat variety, Atlas 66, has a high protein content.
• Iron-fortified rice varieties contain over five times as much iron as in common varieties.

Vegetable crops rich in vitamins & minerals:

Released by Indian Agricultural Research Institute, New Delhi.

• Vitamin A enriched carrots, spinach, pumpkin.
• Vitamin C-enriched bitter gourd, bathua, mustard, and tomato.
• Iron & calcium enriched spinach & bath.
• Protein-enriched beans (broad, lablab, French & garden peas).

Plant Breeding Class 12 Notes

Single Cell Protein (SCP)

It is an alternate source of proteins for animal and human nutrition. example, microbes like Spirulina.

• Spirulina is rich in protein, minerals, fats, carbohydrates & vitamins. It is grown on materials like wastewater from postprocessing plants, straw, molasses, animal manure & sewage.
• This also reduces environmental pollution.
• A 250 Kg cow produces only 200 g of protein/day.
• But 250g of a micro-organism like Methylophilus methylotrophus produces 25 tonnes of protein/day.

NEET Study Material for Strategies for Enhancement in Food Production Chapter

Tissue Culture

A technique of growing plant cells/tissues/organs in a sterile culture medium under controlled aseptic conditions.

• The ability to generate a whole plant from any cell/explant is called totipotency. An explant is any part of a plant that is grown in a test tube under sterile nutrient media.
• The nutrient medium must provide a carbon source (such as sucrose), inorganic salts, vitamins, amino acids, and growth regulators like auxins, cytokinins, etc.
• The method of producing thousands of plants in a very short time through tissue culture is called micropropagation. These plants will be genetically identical original plant, i.e., they are somaclones.
• Tomato, bananas, apples, etc. are produced by this method.
• Tissue culture is used for recovering healthy plants from diseased plants. The meristem (it will be free of virus) from the infected plant is removed and grown in vitro to obtain virus-free plants. Scientists have cultured meristems of banana, sugarcane, potato, etc.

Plant Breeding Class 12 Notes

Somatic hybridization:

• It is the fusion of protoplasts from different varieties of plants (with desirable characteristics) to get hybrid protoplasts. It can be grown from a new plant called somatic hybrid.
• Protoplasts can be isolated after digesting the cell walls of single cells of plants.
• A protoplast of tomatoes has been fused with that of potatoes, forming new hybrid plants called pomatwith characteristics of tomato and potato.
• But it has all the desired characteristics for its commercial utilization.