CBSE Class 12 Biology –Chapter 9 Strategies for Enhancement in Food Production- Study Materials

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Improvement in food production : Notes and Study Materials

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Examples and Exercise

STRATEGIES FOR ENHANCEMENT IN FOOD PRODUCTION
 
I. 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 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.
 
Management of Farms & Farm Animals
 
1. Dairy Farm Management (Dairying)
 
– It is the management of animals for increasing yield and quality of milk and its products.
– Milk yield depends on the quality of breeds in the farm.
– It is important to select good breeds having high yielding potential and resistance to diseases.
– Ways for the yield potential:
o Look after the cattle (housing well, give adequate water and maintain disease free).
o Feeding of cattle in a scientific manner – emphasis on the quality and quantity of fodder.
o Stringent cleanliness and hygiene of cattle & handlers while milking, storage and transport of the milk.
– Nowadays, these processes have mechanized. It reduces chance of direct contact of the produce with the handler.
– To ensure these stringent measures there should be
o Regular inspections to identify and rectify problems.
o Regular visits by a veterinary doctor.
 
2. Poultry Farm Management
 
– Poultry is the domesticated birds used for food or eggs. E.g. chicken, ducks, turkey and geese.
– Components of poultry farm management:
o Selection of disease free and suitable breeds.
o Proper and safe farm conditions.
o Proper feed and water.
o Hygiene and health care.
Animal Breeding
 
– A breed is a group of organisms related by descent and similar general appearance, features, size etc.
– Breeding is the modification of genotype of an organism to make that organism more useful to humans. E.g. Jersey (improved cattle breed), Leghorn (improved chicken breed).
– Animal breeding aims at increasing the yield of animals and improving the desirable qualities of the produce.
– Breeding is 2 types: Inbreeding and out-breeding.
 
a. Inbreeding
 
It is the mating of more closely related individuals within the same breed for 4-6 generations. This strategy is as follows:
o Identify and mate superior males & females of same breed.
o 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.
 
Advantages of Inbreeding:
 
o It increases homozygosity to evolve a pure line animal.
o It exposes harmful recessive genes that are eliminated by selection.
o It helps in accumulation of superior genes and elimination of less desirable genes. This increases the productivity of 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.
b. Out-breeding
 
It is the breeding of the unrelated animals. It includes out-crossing, cross-breeding and inter-specific hybridization.
 
i) Out-crossing:
 
– It is the mating of animals within the same breed, but having no common ancestors on either side of their pedigree up to 4-6 generations.
– The offspring of such a mating is known as out-cross.
– It is the best method for animals having low milk productivity, growth rate in beef cattle, etc.
– It helps to overcome inbreeding depression.
 
ii) Cross-breeding:
 
– It is the mating of superior males of one breed 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.
– E.g. Hisardale (sheep) developed in Punjab by crossing Bikaneri ewes and Merino rams.
 
iii) Interspecific hybridization:
 
– It is the mating of male and female of two different species.
– In some cases, the progeny may combine desirable features of both the parents, and may be of considerable economic value. E.g. Mule (male ass X female horse).
 
Controlled breeding experiments
 
1. Artificial insemination
 
– The semen collected from male parent is injected into the reproductive tract of selected female by the breeder.
– Semen is used immediately or is frozen and used later. Frozen semen can also be transported.
– Success rate of crossing mature male & female is low even though artificial insemination is carried out.
 
2. Multiple Ovulation Embryo Transfer Technology (MOET)
 
– It is a programme for herd improvement. It improves chances of successful production of hybrids.
– In this, a cow is administered hormones such as FSH to induce follicular maturation & super ovulation (production of 6-8 eggs per cycle instead of one egg).
– The animal is either mated with an elite bull or artificially inseminated. Fertilised eggs at 8–32 cells stage are recovered non-surgically 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.
 
Bee-keeping (apiculture)
 
– It is the maintenance of hives of honeybees to produce honey and beeswax.
– Most common species that can be reared is Apis indica.
– Honey is a food of high nutritive and medicinal value.
– Beeswax is used in 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:
(i) Knowledge of the nature and habits of bees.
(ii) Selection of suitable location for keeping beehives.
(iii) Catching and hiving of swarms (group of bees).
(iv) Management of beehives during different seasons.
(v) Handling and collection of honey and beeswax.
– Bees are the pollinators of crop species such as sunflower, Brassica, apple and pear.
– Keeping beehives in crop fields during flowering period increases pollination. It improves crop and honey yield.
 
Fisheries
 
– Fishery is an industry of catching, processing or selling of 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 (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.
 
I. 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 the agriculture. It was dependent on plant breeding.
– Classical plant breeding involves hybridization of pure lines and artificial selection to produce desirable traits.
– Now molecular genetic tools are used for plant breeding.
Desirable traits for plant breeding:
o Increased crop yield and quality.
o Increased tolerance to environmental stresses (salinity, extreme temperatures & drought).
o Increased resistance to insect pests and pathogens.
 
Steps of Plant breeding
 
(i) 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 pre-requisite 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.
 
(ii) Evaluation and selection of parents
 
– The germplasm is evaluated for identifying plants with desirable characters.
– Selected plants are multiplied and used for hybridisation.
– Pure lines are created wherever desirable and possible.
 
(iii) Cross hybridisation of the selected parents
 
– In this, desired characters are genetically combined from 2 different parents to produce hybrid plant.
– E.g. high protein quality of one parent is combined with disease resistance from another parent.
– Limitations:
o Very time–consuming and tedious process.
o Hybrids may not combine the desirable characters. Usually only hundreds to a thousand crosses show the desirable combination.
(iv) 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), so that the characters will not segregate in the progeny.
 
(v) 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 research fields and recording their performance under ideal fertiliser 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).
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).
– During 1960-2000, wheat production increased from 11 million tons to 75 million tons. The rice production increased from 35 million tons to 89.5 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 poor sugar content & yield) was crossed with Saccharum officinarum (tropical canes in south India, thicker stems and higher sugar content but do not grow well in north India) and got a hybrid sugar cane having desirable qualities like high yield, thick stems, high sugar and ability to grow in north India.
 
Millets: Hybrid maize, jowar & bajra developed in India. It includes high yielding varieties resistant to water stress.
 
Plant Breeding for Disease Resistance
 
– Plant diseases cause crop losses up to 20-30% or even total.
– Disease-resistant cultivars enhance 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:
o Fungal: Rusts. E.g. brown rust of wheat, red rot of sugarcane and late blight of potato.
o Bacterial: Black rot of crucifers.
o Viral: Tobacco mosaic, turnip mosaic, etc.
 
Methods of breeding for disease resistance
1. Conventional breeding: The steps are:
o Screening germplasm for resistance sources.
o Hybridisation of selected parents.
o Selection and evaluation of the hybrids.
o Testing and release of new varieties.
Some crop varieties bred by Conventional method
 
Crop
Variety
Resistance to
Wheat
Himgiri
Leaf & stripe rust, hill bunt
Brassica
Pusa swarnim (Karan rai)
White rust
Cauliflower
Pusa Shubhra,
Pusa Snowball K-1
Black rot and curl blight black rot
Cowpea
Pusa Komal
Bacterial blight
Chilli
Pusa Sadabahar
Chilly mosaic virus, Tobacco mosaic virus and leaf curl.
– Conventional breeding is constrained by the availability of limited number of disease resistance genes.
– Inducing mutations in plants and screening them for resistance help to identify desirable genes. Such plants can be multiplied directly or can be used in breeding.
– Other breeding methods are selection amongst somaclonal variants and genetic engineering.
 
2. Mutation breeding:
 
Mutation (sudden genetic change) can create new desirable characters 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 characters. Such plants are selected and multiplied directly or used as a source in breeding.
E.g. In mung bean, resistance to yellow mosaic virus and powdery mildew were induced by mutations.
– Resistant genes from wild species have introduced into the high-yielding cultivated varieties. E.g. 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.
– Resistance genes can be transferred by sexual hybridisation between the target and the source plant.
 
Plant Breeding for Developing Resistance to Insect Pests
 
– Morphological, biochemical or physiological characteristics give insect resistance in host crop plants. E.g.
o Hairy leaves: E.g. resistance to jassids in cotton and cereal leaf beetle in wheat.
o Solid stems in wheat lead to non-preference by the stem sawfly.
o Smooth leaved and Nectar-less cotton varieties do not attract bollworms.
o High aspartic acid, low nitrogen and sugar content in maize leads to resistance to maize stem borers.
– Sources of resistance genes for breeding are cultivated varieties, germplasm collections of crop or wild relatives.
 
Some crop varieties bred for insect pest resistance
 
Crop
Variety
Insect pests
Brassica (rapeseed mustard)
Pusa Gaurav
Aphids
Flat bean
Pusa Sem 2,
Pusa Sem 3
Jassids, aphids & fruit borer
Okra (Bhindi)
Pusa Sawani,
Pusa A-4
Shoot and Fruit borer
Plant Breeding for Improved Food Quality
 
– More than 840 million people in the world do not have adequate food. 3 billion people suffer from micronutrient, protein and vitamin deficiencies (‘hidden hunger’).
– Breeding crops with higher levels of nutrients is called Biofortification. It helps to improve public health.
 
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 for hybrids with improved nutritional quality:
 
o Maize hybrids having twice the amount of amino acids, lysine & tryptophan compared to existing maize hybrids.
o Wheat variety, Atlas 66, having high protein content.
o Iron-fortified rice variety containing over five times as much iron as in common varieties.
o Vitamins & mineral rich vegetable crops: Released by Indian Agricultural Research Institute, New Delhi.
§ Vitamin A enriched carrots, spinach, pumpkin.
§ Vitamin C enriched bitter gourd, bathua, mustard, tomato.
§ Iron & calcium enriched spinach & bathua.
§ Protein enriched beans (broad, lablab, French & garden peas).
 
III. SINGLE CELL PROTEIN (SCP)


– It is the protein derived from single-celled organisms.
– It is an alternate source of proteins for animal and human nutrition. E.g. Spirulina (a blue green alga), Methylophilus methylotrophus (a bacterium).
– Spirulina is rich in protein, minerals, fats, carbohydrate & vitamins. It is grown on materials like waste water from potato processing plants, straw, molasses, animal manure & sewage. This also reduces environmental pollution.
– A 250 Kg cow produces only 200 g protein/day. But 250 g Methylophilus methylotrophus produces 25 tonnes protein. It is due to high rate of biomass production and growth.

IV. TISSUE CULTURE

– A technique of growing plant cells/tissues/organs in 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 very short time through tissue culture is called micropropagation.
– These plants will be genetically identical to original plant, i.e., they are somaclones.
– Tomato, banana, apple etc. are produced by this method.
– Tissue culture is also used to recover healthy plants from diseased plants. The meristem (it will be virus-free) from infected plant is removed and grown in vitro to obtain virus-free plants. Scientists have cultured meristems of banana, sugarcane, potato, etc.
– Somatic hybridization: It is the fusion of protoplasts from two different varieties of plants (with desirable characters) to get hybrid protoplasts. It can be grown to form a new plant called somatic hybrids. Protoplasts can be isolated after digesting the cell walls of plant cells.
E.g. Protoplast of tomato + protoplast of potato → pomato.
This hybrid plant has the characteristics of tomato & potato. But it has no all desired characteristics for its commercial utilization.

CBSE Class 12 Biology Important Questions Chapter 9 – Strategies for Enhancement in Food Production

1 Mark Questions

Chapter 9
Strategies for Enhancement in Food Production

1 Marks Questions
1.Why is inbreeding necessary in animal husbandary?
Ans.Inbreeding increases homozygosity.

2. Name two fungal diseases of Crop plants.
Ans. Brown rust of wheat, Smut of wheat, red rot of Sugar cane, Late blight of potato.

3. Which product of Apiculture is used in cosmetics and polishes?
Ans. Beewax.

4. Semi-dwarf varieties of a crop plant were derived from IR-8. Name that crop.
Ans. Paddy crop (rice)

5. Write two qualities of Saccharum officinarum (Sugarcane) grown in South India.
Ans. Thicker stem and higher sugar content.

6.Name any two semi – dwarf varieties of wheat introduced into all wheat growing places of India?
Ans. Sonalika & Kalyan sona.

7.What is Biofortification?
Ans. The breeding of crops to increase the levels of vitamins, minerals & higher proteins & healthier fats content is called biofortification.

8.Give an example where mutation breeding has been Successfully carried out for introducing disease resistance.
Ans. varieties of mung bean have been successfully developed that are resistant to yellow mosaicvirus & powdery mildew.

9.Name two better yielding varieties of rice developed in India?
Ans. Jaya & Ratna

10.Name the microbe that is grown for use as protein – rich food?
Ans. Methylophilus methylotropous.

11.Why is mutation breeding necessary for breeding for disease resistance?
Ans. because there is limited availability of disease – resistance genes in the crop plants & wide varieties.

12.Give any two commercial products produced from Apis species?
Ans. Honey & bee wax

13.What is the major advantage of producing plants by micropropagation?
Ans. a large number of plants can le grown in a short period of time.

14.What is a somaclones?
Ans. Somaclones are the genetically identical plants developed from any part of a plant laymicropropagation.

15.Name any two fresh water fishes?
Ans. Rohu & catla.

2 Mark Questions

Chapter 9
Strategies for Enhancement in Food Production

2 Marks Questions
1. A new breed of sheep was developed in Punjab by crossing two different breeds of Sheep. Name the two breeds which were crossed and the new breed developed.
Ans.By crossing Bikaneri ewes and Marino rams, the new breed Hisardale was developed.

2. Study the table given below and fill in the blanks marked A, B, C and D

S.No Crop VarietyResistant to Disease
1. 
2.
3.
4.		Wheat 
Brassica
(C)
Chilli		Himgiri 
(B)
Pusa Koma
(D)		(A) 
White rust
Bacterial blight
Chilly mosaic Virus, Tobacco
mosaic Virus and leaf curl

Ans.A – Leaf and Stripe rust, hill bunt.
B – Pusa swarnim (Karan rai).
C – Cowpea
D – Pusa Sadabahar

3. Why are proteins synthesized from Spirulina called Single celled Proteins? What is the significance of such a protein?
Ans.The protein rich food produced by microbes is called as single called protein (SCP) Spirulina is a microorganisms which has more protein. It is a quick method of protein production because the growth rate of microbes is enormous. Hence, it provides a protein rich diet for human beings.

4. Differentiate between inbreeding and outbreeding in animals.
Ans.When breeding is between animals of the same breed, it is callednbreeding, while cross between different breeds in called out breeding.

5. Observe the process of Somatic hybridisation given below and fill in the blanks. (i), (ii), (iii) and (iv)

Ans.(i) Isolation of protoplast of Tomato cell and Potato cell.
(ii) Somatic hybridisation.
(iii) Pomato
(iv) Somatic hybrid

6.What is single cell protein? What is its significance?
Ans.The production of edible proteins on a large scale from microorganisms for human beings &animals is called Single cell protein. It is important because :-

  1. it provide protein – rich supplement in diet.
  2. It reduces pressure on agriculture for supply of desired proteins.
  3. It helps to minimise environmental pollution

7.Expand MOET. How is it carried out?
Ans.Moet is multiple ovulation Embryo transfer. It involves following steps :-

  1. a cow is administered hormones to induce follicular motivation & super ovulation.
  2. Cow is mated with a selected bull.
  3. Fertilized eggs at 8-32 celled stage are recovered & transferred to surrogate mother.

8.What is germplasm? Why is it necessary to have gemplasm collection?
Ans.The sumtotal of all the alleles of the gene present in a plant & its relative is called Germplasm. Germplasm collection is very essential for effective exploitation of natural genes available in the population.

9.What is inbreeding depression? Why do self – pollinated crops do not show the ill-effects of inbreeding depression?
Ans.Continued inbreeding especially close inbreeding usually reduces fertility & even productivity.This is called inbreeding depression. In self – pollinated crops, since the male & female reproductiveparts are of the same flower & are compatible with each other to cause fertilisation : it does notshow ill – effects of inbreeding depression.

10.What is interspecific hybridization. Give an example?
Ans.It is a method of outbreeding in which male & female animal of two different species are crossed to combine the desirable features of both the parents into one eg, mule is produced by a cross between donkey & a female horse.

11.What are the advantages of breeding for disease-resistance in plants?
Ans. Plant breeding for disease resistance has two advantages
i)Enhance food production lay reducing losses due to diseases.
ii)Reduced dependence on use of fungicides & bacteriocides

12.Which part of the plant is best suited for making virus free plants & why?
Ans.Apical & intercalary buds having apical mexistem are best suited part of the plant body for making virus free plants as they are free from viral infection.

13.What is artificial insemination? What are the advantages of this technique?
Ans.It is a process in which the semen collected from a superior male is injected into the reproductivetract of the selected female by the breeder.
Advantages :-

  1. Semen can be used immediately or stored
  2. Semen can be transported in frozen from to a distant place.
  3. Semen from one selected made can be used on number of females.

14.Why was hybridization carried out between species of Sugarcane in North India & that grown in south India?
Ans.Saccharum barberi grown in North India but had poor sugar content & Yield. Saccharum officarumhad thicker Stem & high sugar content but cannot grow well in north India. The hybrid of these twovarieties has desirable quality of high yield, thick stem, high sugar & ability to grow in North India.

15.Name the variety developed & disease to which it is resistant in case of :-
i) Brassica
ii) Cowpea
Ans.i) Pusa swarnim variety developed against white rust.
ii) Pusa komal variety developed against Bacterial blight.

16.What is meant by the term “breed”. What are the objectives of animal breeding?
Ans.The group of animal having similar ancestral characters size, general appearance etc – are calledbreed.
Objectives of Animal Breeding :-
(a) Increase the yield of animals.
(b) Improvement in the desirable qualities of the produce.

3 Mark Questions

Chapter 9
Strategies for Enhancement in Food Production

3 Marks Questions
1. What is micropropagation? Why are plants produced by this technique called somaclones? Name any two food plants which are produced on commercial scale using this method.
Ans. The method of producing many plants through tissue culture is called micropropagation.
The plants produced through micropropagation will be genetically identical to the original plant from which they were grown, hence are called somaclones.
Tomato, banana, apple are produced on commercial scale using this method.

2. What is mutation? Explain the significance of mutation in plant breeding. Give an example of a disease resistant variety of cultivated plant induced by mutation.
Ans.Mutation : Sudden inheritable change in the characters of an organism due to change in the sequence of bases in the gene(s).
Mutation results in a new character or trait, not found in the parental type It can also be induced by using mutagens like gamma radiations.
Such plant materials are used as such or used for breeding new variaties.
Mung bean resistance to yellow mosaic virus and powdery mildew.

3. How can we improve the success rate of fertilisation during artificial insemination in aminal husbandary programmes?
Ans.The Multiple Ovulation Embryo Transfer (MOET) technology can improve the success rate of fertilisation.
In the procedure, a cow is given hormonal treatment (FSH), so that more than one ova/eggs (6-8) are produced per cycle. After mating or artificial insemination the embryos at 8-32 celled stage, are transferred to different surrogate mother cows. This technology has been successfully used for cattle sheep, rabbit, mares and buffalloes.

4. Biofortification is the most practical means to improve public health. Justify the statement with examples.
Ans.Biofortification is the plant breeding programme designed to increase Vitamins, minerals, heigher proteins and healthier fat content in crops. This programme improves the quality of food products. It is required to prevent hidden hunger. Some of the examples of fortified crops are:
(i) New hybrid of maize : has twice the amount of amino acid lysine and tryptophan.
(ii) Wheat : Atlas 66, having a high protein content.
(iii) Rice : 5 times iron than the normal amount. IARI Delhi has released several crops which are rich in vitamins and minerals. Consumption of such biofortified food will vastly improve the public health.

5. What is meant by germplasm Collection? Describe its significance in plant breeding programmes.
Ans.The collection of all the diverse alleles of all the genes of crop plant is called germ plasm collection.
In plant breeding programmes, the germplasm provides the entire of genes and alleles, and the characterstics which they express. The plant breeders select the most favourable characters of a particular gene and manipulate its transfer to a desirable parent.

6. To which product, following products are related (a) Blue revolution (b) white revolution (c) Green revolution
Ans. (a) Fish production (b) Milk production (c) Crop production

7.What measures would you undertake to improve the quality & quantity of milk production?
Ans.The quality & quantity of milk production depends on three factors :-

  1. Genetic makeup.
  2. Nutrition &
  3. Environment

Thus, the following steps should be taken to improve management of livestock :-
a.SHEDS :- Sheds should be neat & clean, well – ventilated with pucca floor & will drained channel.
b.BALANCED DIET :- a balanced feed consists of appropriate quantities of carbohydrates, proteins, vitamins, minerals & water. The feed consists of two main components :-
i.Roughage – include fodder, hay, straw & Silage.
ii.Concentrates – broken forge crops, grams, cereals, mullets, cotton, seeds.
a.CLEAN WATER :
b.HEALTH CARE:- It requires regular inspection with proper record keeping.

8.What is “tissue culture”. What are the steps involved in tissue culture?
Ans.“Tissue culture is an experimental process through which a mass of cells (callus) is produced froman explant tissue & used directly to regenerate plant It invoices following steps :-

  1. Selection of an elite plant
  2. Preparation of suitable culture media
  3. Sterilisation of an explant & inoculation on culture media under controlled temp ~ 250 c in light
  4. Callus induction in explant.
  5. Organogenesis :- a high cytokine : auxin ratio induce Shoot formation while high auxin : cytokinin ratio induce root formation.
  6. Acclamatization :- test tube rooted plantlets are first subjected to acclimatization in green house & then transferred to the field.

9.What are the measures that need to be taken for effective poultry farm management?
Ans.i) It requires a crowd – free, rainproof, well ventilated & protected brood house.
ii).Brood house should be clean & disinfected.
iii).Good drainage system.
iv).Proper fed & clean & fresh drinking water.
v).Proper light management for optimum egg production.
vi).Poultry are more sensitive to heat so, measures should be adopted to overcome heat shock.
a).Sheds should be covered with grass or low vegetation.
b).Provide sprinklers on roof.
c).Maximum Ventilation.
vii)Disease – free & suitable breeds should be selected for breeding.

10.The steps in a programme are :-
Collection of germplasm, crossbreeding the selected parents, selection superior recombinant progeny & Testing, releasing & marketing new cultivars?
i) What is this programme related to?
ii) Name two special qualities as the basis of selection of progeny.
iii) What was the outcome of the programme?
iv) What is the popular term given to this outcome? Also name the India Scientist who is credited with chalking out of this programme.
v) Among the above – mentioned step which is the most crucial step of this programme& why?
Ans. i). Plant breeding.
ii). Disease resistance & yield.
iii). Production of improved varieties.
iv). The popular term give to this outcome is HYBRID. Dr. S. Swamminathan is credited with chalking out of this programme.
v). Selection of superior progeny is the most crucial step of this programme because it yields plants thatare superior to both parents & are then self – pollinated for several generations.

11. What is apiculture? What are the requirements to consider for bee–keeping?
Ans.The culturing of honey bees for the production of honey or beewax is called Apiculture.
Bee – keeping can be practised in any area where there is sufficient bee pastures of some wild shrubs, fruits orchards & cultivated crops. The following points are important for successful bee – keeping :-

  1. Knowledge of nature & habits of bee.
  2. Selection of suitable location of keeping beehives.
  3. Catching & hiving of swarms.
  4. Management of beehives during different seasons.
  5. Handling & collection of honey &beewax.

12.What are the major steps involved in Plant breeding?
Ans.The major steps involved in plant breeding are :-
i). Collection of varieties :- collection & preservation of all the different wild varieties, species & relatives ofthe cultivates species.
ii). Evaluation & Selection of Parents :- Germplasm collected is evaluated to identify plants with desirablecharacter. The selected plants are multiplied & used.
iii). Hybridisation of Selected Parents :- The selected parents are hybridized so that the traits in them can becombined in the hybrid progeny.
iv). Selection & Testing of Superior Recombinants :- Individuals with desired combination of characters haveto be selected from among the progeny. Such hybrids are superior to both the parents.
v). Testing, Release & commercialization of New cultivars :-
Evaluation is done by growing these plants in the research field & recording their performance under ideal conditions of irrigation, fertilizers & other crop practices. The selected plants are then tested in the farmer’s field for at least three growing seasons. The material thus selected is certified & released as a variety.

5 Marks Questions

Chapter 9
Strategies for Enhancement in Food Production

5 Marks Questions
1. Does apiculture offer multiple advantages to farmers? List its advantages, if it is located near a place of commercial flower cultivation. Name the most common species of bee which is reared in India.
Ans. Apiculture or Bee-Keeping is the maintenance of hives of honeybees for the production of honey. Apiculture is beneficial for farmers in many ways. Honey bee also produces beewax which is used in industries, such as in preparation of cosmetics and polishes of various kinds. If Bee keeping is practiced in any area the commercial flowers are cultivated, it will be beneficial in the following ways.
(i) Bees are pollinators of many crop species including flowering crops such as sunflower.
(ii) It improves the honey yield, because honeybees collect the nectar from flowers for making honey.
Apis indica is the msot common species whch is reared in India.

2. What is somatic hybridisation? Describe the various steps in producing somatic hybrids from protoplasts. Mention any two uses of somatic hybridisation.
Ans. Somatic Hybridisation : The process of fusing protoplasts of Somatic cells derived from different varieties or species of plants to produce a hybrid.
Steps :
(i) Removal of cell wall of fusing cells by digestion with a combination of pectinase and cellulase to form protoplasts.
(ii) Fusion between protoplasts of selected parents is induced by the use of poly ethylene glycol (PEG).
(iii) The resulted product is cultured on a suitable medium to regenerate cell walls.
(iv) The cells obtained begin to divide to produce plantlets called somatic hybrids.
Uses/Applications :
(i) Somaclonal variations can be created
(ii) Lines or varieties/species of plants which can not be sexually hybridised, they can be hybridised.
(iii) Allopolyploids can be raised by the method.

3.What do you mean by “Out – breeding”. What are the different methods employed for out breeding.
Ans. Breeding between the unrelated ale & female animals is called Outbreeding. It can be done in following ways:-
i)OUT CROSS :- The mating of animals within the same breed but do not have any common ancestor on either side of their pedigree for 4-6 generation is called an out cross. It is the best method of breeding of animals that are below average in milk production, growth rate of beef cattle etc.
ii)CROSS–BREEDING :- It is a cross between superior males of one breed & Superior females of another breed. It allows the desirable qualities of two different breeds to be combined & are used for commercial production eg . Hisardale, a new breed of sheep is developed by crossing bikaneri ewes & Marino rams.
iii)INTERSPECIFIC HYBRIDISATION :- male & female animals of two different related species are mated so, that progeny may combine desirable features of both parents eg. mule is produced by crossly donkey & a female house.

4.What is somatic hybridization – Explain the steps involved in the production of somatic hybrids?
Ans. Somatic hybridization is the process of fusing protoplasts of somatic cells derived from twodifferent varieties or species of a plant on a suitable nutrient culture medium under sterilecondition. One example of somatic hybrid is topato produced by fusion of protoplast of tomato &potato.
Somatic hybridization involves the following steps:-
I).Isolation of protoplast from two different varieties of plants – each having a desirable character,
II). Fusion of cytoplasm of two protoplast results in coalescence of cytoplasm. The nuclei of twoprotoplasts may or may not fuse together even after fusion of cytoplasm, fusion of protoplast requires a suitable agent called fusogen eg. PEG or polyethylene glycol.
III). Under favourable conditions, hybrid protoplast synthesise new cell wall around it. Hybrid cellfunctions as a single cell & then undergo sustained division to form callus.
IV). The regenerated callus is transferred to a new culture plates containing suitable culture

Strategies for Enhancement in Food Production Class 12 Biology MCQs

1. The technique of obtaining a large number of plantlets by tissue culture method is known as
(a) organ culture.
(b) micropropagation.
(c) plantlet culture.
(d) macropropagation.

Answer

Answer: b

2. Viral disease-free plants are obtained through
(a) anther culture.
(b) shoot meristem culture.
(c) ovary culture.
(d) leaf-cell culture.

Answer

Answer: b

3. Breeding of crops to increase the levels of essential nutrients, is called
(a) biofortification.
(b) biomagnification.
(c) bioinformatics.
(d) biotechnology.

Answer

Answer: a

4. The species of Saccharum (sugarcane) originally grown in North India.is
(a) S. munja.
(b) S. officinarum.
(c) S. barberi.
(d) All of these.

Answer

Answer: c

5. Inbreeding is carried out in animal husbandry because it [NCERT Exemplar]
(a) increases vigour.
(b) improves the breed.
(c) increases heterozygosity.
(d) increases homozygosity.

Answer

Answer: d

6. A group of animals which are related by descent and share many similarities are referred to as [NCERT Exemplar]
(a) breed.
(b) race.
(c) variety.
(d) species.

Answer

Answer: a

7. The biggest constraint of plant breeding is [NCERT Exemplar]
(a) availability of desirable gene in the crop and its wild relatives.
(b) infrastructure.
(c) trained manpower.
(d) transfer of genes from unrelated sources.

Answer

Answer: a

8. Which one of the following combination would a sugarcane farmer look for in the sugarcane crop? [NCERT Exemplar]
(a) Thick stem, long intemodes, high sugar content and disease resistant.
(b) Thick stem, high sugar content and profuse flowering.
(c) Thick stem, short intemodes, high sugar content, disease resistant.
(d) Thick stem, low sugar content, disease resistant.

Answer

Answer: a

9. A collection of all the alleles of all the genes : of a crop plant is called [NCERT Exemplar]
(a) germplasm collection.
(b) protoplasm collection.
(c) herbarium.
(d) somaclonal collection.

Answer

Answer: a

10. Which one of the following is a marine fish? [NCERT Exemplar]
(a) Rohu
(b) Hilsa
(c) Catla
(d) Common Carp

Answer

Answer: b

11. Inbreeding increases ______ .

Answer/Explanation

Answer:
Explaination: Homozygosity.

12. A single ______ helps to overcome inbreeding depression.

Answer/Explanation

Answer:
Explaination: Outcrossing.

13. ______ obtained through apiculture is used in cosmetics and polishes.

Answer/Explanation

Answer:
Explaination: Beewax.

14. ______ variety of wheat is resistant hill bunt disease.

Answer/Explanation

Answer:
Explaination: Himgiri.

15. Pusa Komal is the variety of ______ that is resistant to bacterial blight.

Answer/Explanation

Answer:
Explaination: Cowpea.

16. ______ is used in the production of single cell protein.

Answer/Explanation

Answer:
Explaination: Spirulina.

17. A poultry farm typically includes chicken and ______ .

Answer/Explanation

Answer:
Explaination: Ducks.

18. In MOET, the cow is administered hormones with ______ activity.

Answer/Explanation

Answer:
Explaination: FSH.

19. Mule is produced by hybridisation.

Answer/Explanation

Answer:
Explaination: Interspecific.

20. mothers are involved in MOET.

Answer/Explanation

Answer:
Explaination: Two.

21. Match the items in Column I with those in Column II.

Column I
(Variety of Crop)		Column II
(Resistant to)
A. Pusa Komal of cowpea1. Hill Bunt
B. Pusa Swamim of Brassica2. Blackrot and curl blight
C. Pusa Shubhra of Cauliflower3. Bacterial blight
D. Himgiri of Wheat4. Leaf curl
 5. White rust
Answer/Explanation

Answer:
Explaination: A – 3, B – 5, C – 2, D – 1

22. Match the items in Column I with those in Column II.

Column IColumn II
A. Somaclones1. Spirulina
B. Atlas 66 of wheat2. Resistance to yellow mosaic in mung bean
C. Mutation breeding3. Lysine and tryptophan-rich
D. Single cell protein4. High protein content
E. Maize hybrids5. Micro-propagation
Answer/Explanation

Answer:
Explaination: A – 5, B – 4, C – 2, D – 1, E – 3

23. Pomato is the somatic hybrid between potato and tomato. [True/False]

Answer/Explanation

Answer:
Explaination: True.

24. Explants are the dead plants. [True/False]

Answer/Explanation

Answer:
Explaination: False.

25. Pusa Sawani is the variety of Okra resistant to shoot and fruit borer. [True/False]

Answer/Explanation

Answer:
Explaination: True.

26. Germplasm collection is not necessary for plant breeding programmes. [True/False]

Answer/Explanation

Answer:
Explaination: False.

27. Outcrossing is the practice of mating animals within the same breed. [True/False]

Answer/Explanation

Answer:
Explaination: True.

Directions: (Q28 to Q30): Mark the odd one in each of the following groups.
28. Red rot of sugarcane, Black rot of crucifer, Late blight of Potato, Brown rust of wheat.

Answer/Explanation

Answer:
Explaination: Black rot of crucifer.

29. Outcrossing, Inbreeding, Inter-specific hybridisation, Cross-breeding.

Answer/Explanation

Answer:
Explaination: Inbreeding.

30. Chilli mosaic virus, Tobacco Mosaic virus, Leaf curl, Curl blight.

Answer/Explanation

Answer:
Explaination: Curl blight.

31. What is dairying?

Answer/Explanation

Answer:
Explaination: Dairying is the management of animals for milk and milk products for human consumption.

32. Name the two factors on which the yield of milk depends.

Answer/Explanation

Answer:
Explaination:
Milk yield depends on:
(i) the quality of the breed.
(ii) the type of feed.

33. Mention the strategy used to increase homozygosity in cattle for desired traits.

Answer/Explanation

Answer:
Explaination: Inbreeding, i.e. mating of more closely related individuals of the same breed, for 4-6 generations.

34. A herd of cattle is showing reduced fertility and productivity. Provide one reason and one suggestion to overcome this problem. [AI2017]

Answer/Explanation

Answer:
Explaination:
– It is inbreeding depression that arises due to continued and close inbreeding.
– It can be overcome by mating the selected animals of the breeding population with unrelated superior animals of the same breed, i.e., outcrossing.

35. Suggest the breeding method most suitable for animals that are below average in milk productivity. [Delhi 2016]

Answer/Explanation

Answer:
Explaination: Outcrossing, a method of outbreeding is the most suitable for this; it is the mating of animals within the same breed, but having no common ancestors on either side of then- pedigree upto 4-6 generations.

36. What is the significance or advantage of outcrossing?

Answer/Explanation

Answer:
Explaination:
– It helps to overcome inbreeding depression.
– It is the best breeding method to improve in milk yield, growth rate (beef cattle), etc.

37. How is Hisardale produced?

Answer/Explanation

Answer:
Explaination: Hisardale is produced by crossing Bikaneri ewes and Marino rams.

38. Write a professional approach at genetic level that can help the farmer to improve the milk yield of low milk-producing cows in his farm. [Delhi 2013C]

Answer/Explanation

Answer:
Explaination: Outcrossing.

39. Write the importance of MOET. [Delhi 2013]

Answer/Explanation

Answer:
Explaination: High milk-yielding breeds of females and high meat-yielding bulls are bred to increase the herd size in a short time through MOET.

40. Mention the role of ‘genetic mother’ in MOET. [AI 2016]

Answer/Explanation

Answer:
Explaination:
– The genetic mother is induced superovulation, i.e., production of 6-8 eggs for cycle instead of one and mated with an elite bull or artificially inseminated; fertilisation and development of embryo (8-32 celled stages) occurs in the genetic mother.

41. Mention the economic value of Apis indica. [Delhi 2015 C]

Answer/Explanation

Answer:
Explaination: It is the most common species of honey bee employed in apiculture.

42. List any two economically important products for humans obtained from Apis indica.

Answer/Explanation

Answer:
Explaination: Honey and beewax.

43. What is meant by fishery?

Answer/Explanation

Answer:
Explaination: Fishery is an industry dealing with catching, rearing, processing and selling of fishes, and shell-fishes like molluscs and crustaceans

44. What is blue revolution?

Answer/Explanation

Answer:
Explaination: Blue revolution is the movement launched in the same lines as green revolution, to increase the production of fish and fish products.

45. List the two steps, the classical plant breeding involves.

Answer/Explanation

Answer:
Explaination:
The two steps include:
(i) crossing or hybridisation of pure lines..
(ii) Artificial selection of plants with desirable traits.

46. Which of the following is the semi-dwarf wheat that is high-yielding and disease-resistant?
Pusa Shubra, Kalyan Sona, Ratna.

Answer/Explanation

Answer:
Explaination: Kalyan Sona.

47. Write the names of two semi-dwarf and high-yielding rice varieties developed in India after 1966. [Delhi 2012]

Answer/Explanation

Answer:
Explaination: Jaya and Ratna

48. State the economic value of Saccharum officinarum in comparison to S. barberi. [AI 2015 C]
Or
Why is the South Indian sugar cane preferred by agriculturists? [Foreign 2012]

Answer/Explanation

Answer:
Explaination:
– Saccharum officinarum has thicker stems , and higher sugar content.
– Saccharum barberi has poor sugar content and yield.

49. Write the names of the two millet crops in which hybrids have been developed in India.

Answer/Explanation

Answer:
Explaination: Jowar, Bajra.

50. Name any two diseases the ‘Himgiri’ variety of wheat is resistant to. [AI 2013]

Answer/Explanation

Answer:
Explaination:
(i) Leaf and stipe rust
(ii) Hill bunt.

51. How has mutation breeding helped in improving the production of mung bean crop? [Delhi 2015]

Answer/Explanation

Answer:
Explaination: Through mutation breeding, mung bean has been made resistant to yellow mosaic virus and powdery mildew disease.

52. State the importance of biofortification.[AI 2011]

Answer/Explanation

Answer:
Explaination: Biofortification is important to improve public health, as about three billion people suffer from deficiency of micronutrients, proteins and vitamins.

53. Write an alternate source of proteins for animals and human nutrition. [AI 2014]

Answer/Explanation

Answer:
Explaination: Single cell protein.

54. Name the organism commercially used for the production of single cell protein.
Or
Which of the following produces single cell proteins?
Sonalika, Spirulina, Saccharomyces.

Answer/Explanation

Answer:
Explaination: Spirulina.

55. Identify the two correct statements from the following: [Delhi 2014C]
(i) Apiculture means apical meristem culture.
(ii) Spinach is iron-enriched.
(iii) Green revolution has resulted in improved pulse-yield.
(iv) Aphids cannot infest rapeseed mustard.

Answer/Explanation

Answer:
Explaination: (ii) and (iv) are correct statements.

Class 12 Biology All Chapters
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