VBQs Class 12 Biology Strategies for Enhancement in Food Production

Please refer to VBQs for Class 12 Biology Strategies for Enhancement in Food Production. All value based questions for Biology Class 12 have been provided with solutions. We have provided below important values questions and answers. Students should learn these solved VBQs for Class 12 Biology as these will help them to gain more marks and help improve understanding of important topics.

Strategies for Enhancement in Food Production VBQs Class 12 Biology with Answers

Animal Husbandry

Very Short Answer Type Questions

Question. Write the importance of MOET. 
Answer. Multiple Ovulation Embryo Transfer Technology (MOET) is the programme used to increase the herd size in a short time.

Question. List any two economically important products for humans obtained from Apis indica.
Answer. Honey and beewax are two economically important products obtained from Apis indica.

Question. Mention the role of ‘genetic mother’ in MOET.
Answer. In MOET, genetic mother is the biological mother of the offspring. Hormones with FSH like activity are given to genetic mothers for inducing follicular maturation and superovulation. As a result, 6-8 eggs are produced instead of 1 egg per cycle. She is then mated with a superior bull or artificially inseminated. Embryos at 8-32 cell stage are recovered and transferred to surrogate mother and the genetic mother is again available for super ovulation.

Question. Mention the economic value of Apis indica.
Answer.Apis indica is common species of honey bee used in apiculture.

Question. Write the name of the following :
(a) The most common species of bee suitable for apiculture.
(b) An improved breed of chicken. 
Answer.(a) Apis indica
(b) Leghorn is an improved breed of chicken.

Question. Suggest the breeding method most suitable for animals that are below average in milk productivity. 
Answer.Outcrossing is the most suitable breeding method for animals that are below average in milk productivity. It is the mating of animals within the same breed but having no common ancestors on either side of their pedigree upto 4-6 generations.

Question. Write a professional approach at genetic level that can help the farmer to improve the milk yield of low milk producing cows on his farm.
Answer.Outcrossing is the best breeding method and professional approach that can help farmer improve the milk yield in animals that are below average in milk production.

Short Answer Type Questions

Question. Which one of the following is used in apiculture ?
Hilsa, Apis indica, Sonalika 
Answer. Apis indica is the most common species of bees used in apiculture. Hilsa is a marine fish. Sonalika is the high yielding and disease resistant variety of the wheat.

Question. Explain giving reasons, the need to keep the bee-hives in the fields during flowering season.
Answer. Bees are the pollinators of many of our crop species such as sunflower, Brassica, apple and pear. Keeping beehives in crop fields during flowering period increases pollination eficiency and improves the crop yield. Also bees collect nectar from flowers of these crop plants to make honey hence, honey yield also increases.

Question. What is meant by the term breed ? What are the objectives of animal breeding? 
Answer.A group of animals related by descent and similar in most characters like general appearance, features, size, configuration etc, is called a breed.
The main objectives of animal breeding are :
(i) To produce high yielding varieties of animals like high milk producing varieties in cattle, more egg producing varieties in chicken, more wool bearing varieties in sheep etc.
(ii) To produce draught or powerful varieties for doing work like in cattle, buffaloes, etc.
(iii) To produce disease resistant varieties in many of the livestocks.

Question. Differentiate between outbreeding and outcrossing. 
Answer. Out breeding is breeding of unrelated animals which may be between individuals of same breed or between different breeds or different species. Outcrossing is the practice of mating of animals within the same breed but having no common ancestors. This is the best breeding method for animals that are below average in milk production, growth rate in beef cattle, etc. A single outcross often helps to overcome inbreeding depression.

Question. How is a pureline in an animal raised ? Explain.
Answer. A pure line in an animal is raised through inbreeding. In this method, superior males and females of the same breed are selected and mated. The progeny obtained from such matings are evaluated and superior males and females among them are identified for further mating. Inbreeding increases homozygosity. It exposes harmful recessive genes that are eliminated by selection.

Question. MOET programme has helped in increasing the herd size of the desired variety of cattle. List the steps involved in conducting the programme.
Answer. Multiple Ovulation Embryo Transfer or MOET is a method to improve the herd size of desired variety of cattle. The steps involved in MOET are as follows:-
(i) Hormones (with FSH-like activity) are given to cow for inducing follicular maturation and super ovulation i.e., production of 6-8 ova in one cycle.
(ii) Cow is either mated with best bull or artificially inseminated.
(iii) The embryos with 8-32 cell stages are recovered and transferred to surrogate mother and genetic mother becomes available for new cycle of super ovulation.

Question. State the disadvantage of inbreeding among cattle. How it can be overcome?
Answer. Continuous inbreeding among cattle leads to reduced fertility and productivity, a phenomenon called inbreeding depression. It can be overcome by mating selected unrelated superior animals of same breed. This helps to restore fertility and yield.

Question. List any four important components of Poultry Farm Management ?
Answer. The four important components of poultry farm management are:-
(i) Selection of disease free and suitable breeds: Selection of breeds is the most important aspect.The breed should be disease free and suitable to the environmental conditions.
(ii) Brood house: Brood house should not be crowded and should be rain proof and protected from predators.
(iii) Sanitation and hygiene: The area should be cleaned and disinfected.
(iv) Feed management: Feeding constitutes the major management concern in egg and meat production.

Short Answer Type Questions

Question. (a) What is the programme called that is involved in improving success rate of production of desired hybrid and herd size of cattle?
(b) Explain the method used for carrying this programme for cows. 
Answer. (a) Multiple Ovulation Embryo Tansfer Technology (MOET) is used for improving success rate of production of desired hybrid and herd size of cattle.
(b) Multiple Ovulation Embryo Transfer Technology (MOET) is a programme for herd size improvement. In this method, hormones (with FSH-like activity) are given to the cow for inducing follicular maturation and superovulation i.e., instead of one egg, which they usually give per cycle, they produce 6-8 eggs. The cow is either mated with the best bull or artificially inseminated. The embryos at 8-32 celled stages are recovered and transferred to surrogate mothers. The genetic mother is available for another super ovulation. MOET has been done in cattle, sheep, rabbits, buffaloes, mares etc. High milk giving breeds of females and high quality meat (lean meat with less lipid) giving bulls have been bred successfully to obtain better breed in a short time.

Question. High yielding cattle is a good solution for food enhancement. How does the MOET technology help to increase the herd size ?
Answer. Multiple Ovulation Embryo Transfer Technology (MOET) is a programme for herd size improvement. In this method, hormones (with FSH-like activity) are given to the cow for inducing follicular maturation and superovulation i.e., instead of one egg, which they usually give per cycle, they produce 6-8 eggs. The cow is either mated with the best bull or artificially inseminated. The embryos at 8-32 celled stages are recovered and transferred to surrogate mothers. The genetic mother is available for another super ovulation. MOET has been done in cattle, sheep, rabbits, buffaloes, mares etc. High milk giving breeds of females and high quality meat (lean meat with less lipid) giving bulls have been bred successfully to obtain better breed in a short time.

Question. (a) Name any two fowls other than chicken reared in a poultry farm.
(b) Enlist four important components of poultry farm management. 
Answer.(a) Poultry is rearing of domesticated fowl (birds) used for their meat and eggs. Two fowls reared in a poultry farm other than chicken are ducks and turkeys.
(b) Important components of poultry farm management are as follows :
(i) Selection of disease free and suitable breeds
(ii) Proper and safe farm conditions
(iii) Proper feed and water
(iv) Hygeine and healthcare

Question. List any three outbreeding practices carried out to breed domestic animals. Explain the importance of each one listed.
Answer. The three outbreeding practices carried out to breed domestic animals are: outcrossing, crossbreeding and interspecific hybridisation. Outcrossing is the mating of animals within the same breed but not having common ancestors on either side of their pedigree up to 4-6 generations. Outcrossing is the best breeding method for animals that are below average in milk production, growth rate in beef and cattle etc. Sometimes only one outcross helps to overcome inbreeding depression.
In cross-breeding superior males of one breed are mated with superior females of another breed. crossbreeding allows the desirable qualities of two different breeds to be combined. The progeny hybrid animals may themselves be used for commercial production. Alternatively, they may be subjected to some form of inbreeding and selection to develop new stable breeds that may be superior to the existing breeds e.g., Hisardale is a new breed of sheep developed by crossing Bikaneri ewes and Marino rams. In interspecific hybridisation, male and female animals of two different species are mated. The progeny obtained from such a mating are usually different from both the parental species. But in some cases, the progeny may combine desirable characters of both the parents. Mule is produced from a cross between female horse (mare) and male donkey.

Question. (a) Explain how to overcome inbreeding depression in cattle.
(b) List three advantages of inbreeding in cattle.
(c) Name an improved breed of cattle.
Answer. (a)Continuous inbreeding among cattle leads to reduced fertility and productivity, a phenomenon called inbreeding depression. It can be overcome by mating selected unrelated superior animals of same breed. This helps to restore fertility and yield.
(b) Three advantages of inbreeding in cattle are:
(i) Inbreeding increases homozygosity. Hence, it is necessary if we want to evolve pureline.
(ii) Inbreeding exposes those recessive genes that are eliminated by selection.
(iii) It helps in accumulation of superior genes and elimination of less desirable genes.
(c) Jersey is an improved breed of cattle.

Question.(a) Write the scientific name of the most common species of honey bee reared.
(b) Mention the kind of areas that are suitable for bee-keeping practices.
(c) Mention any two uses of bee wax.
Answer.(a) (a) Apis indica
(b) Bee-keeping can be practiced in an area where there are suficient bee pastures of some wild shrubs, fruit orchards and cultivated crops.
(c) Beewax is used in cosmetics, creams, ointments,paints and polishes.

Question. Mention and describe any three methods to overcome inbreeding depression in animal husbandry. 
Answer. Continuous inbreeding usually reduces fertility and productivity. This is called inbreeding depression. Inbreeding depression can be overcome by outcrossing, crossbreeding and interspecific hybridisation. Outcrossing is the practice of mating of animals within the same breed, but having no common ancestors on either side for 4-6 generations. A single outcross often helps to overcome inbreeding depression. In cross-breeding superior males of one breed are mated with superior females of another breed. Cross-breeding allows the desirable qualities of two different breeds to be combined. In interspecific hybridisation, male and female animals of two different related species are mated.

Question. Enumerate any six essentials of good, effective dairy farm management practices. 
Answer. Six essentials of good, effective dairy farm management practices are:
(i) Animals should be kept in a well – ventilated shed with a pucca floor and a proper drain channel.
(ii) Cows should be milked gently, quickly, fully and hygienically.
(iii) Shed should be disease free.
(iv) In summer, adequate amount of fresh and clean drinking water should be provided. Sprinkling of water in the shed also reduces the heat stress.
(v) In winter and during rains, the animals should be kept under cover especially at night.
(vi) Regular visit by a veterinary doctor is be mandatory.

Question. Study the flow chart given below :

(a) Identify the events that take place at stages
(1) and (2) respectively.
(b) State the importance of the technology explained above.
Answer.(a) 1. Follicular maturation and superovulation 2. Embryos are transferred to surrogate mother
(b) Multiple Ovulation Embryo Transfer Technology (MOET) is the programme used to increase the herd size in a short time.

Question. Differentiate between inbreeding and outbreeding in cattle. State one advantage and one disadvantage for each one of them.
Answer. When breeding is done between animals of the same breed for 4-6 generations, it is called inbreeding. Outbreeding is the breeding between the unrelated animals which may be between individuals of the same breed (but having no common ancestor for 4-6 generations) i.e., outcrossing or between different breeds (crossbreeding) or different species (interspecific hybridisation).
Advantages : (i) Inbreeding increases homozygosity.It also helps in accumulation of superior genes and elimination of less desirable genes.
(ii) Outbreeding is the best breeding method for animals that are below average in productivity in milk production, growth rate in beef and cattle.
Disadvantages : (i) Continued inbreeding reduces fertility and even productivity. This is called inbreeding depression. (ii) Outbreeding leads to elimination of recessive characters whereas desired combinations of characters may appear in low frequency.

Question. What is ‘Blue revolution’? Name two freshwater and two marine edible fish. 
Answer.  Blue revolution is the movement implemented along the same lines as green revolution related to the production of fish and fish products on a large scale. Freshwater edible fishes are rohu and catla. Marine water edible fishes are hilsa and Bombay duck.
Plant Breeding

Very Short Answer Type Questions

Question. Name any two diseases the ‘Himgiri’ variety of wheat is resistant to. 
Answer. Himgiri variety of wheat is resistant to leaf and stripe rust and Hill bunt diseases.

Question. State the importance of biofortification.
Answer. Biofortification is the breeding of crops with higher levels of vitamins and minerals or higher proteins and healthier fats, to improve the public health by practical means.

Question. State the economic value of Saccharum officinarum in comparison to S.barberi.
Answer.Saccharum oficinarum has higher sugar content and its stems are thicker, while Saccharum barberi has poor sugar content and yield.

Question. Write the names of two semi-dwarf and high yielding rice varieties developed in India after 1966. 
Answer.Jaya and Ratna

Short Answer Type Questions

Question. Name and explain the mechanism by which seeds from hybrid plants are developed, that are able to retain the desired hybrid character in the progeny.
Answer.Plant breeding is the purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better
yields and are disease-resistant. The main steps in plant breeding are:-
(i) Collection of variability
(ii) Evaluation and selection of parents
(iii) Cross hybridisation among the selected parents
(iv) Selection and testing of superior recombinants
(v) Testing, release and commercialisation of new cultivars.

Question. Name any two common Indian millet crops.State one characteristic of millets that has been improved as a result of hybrid breeding so as to produce high yielding millet crops.
Answer.Jowar and bajra are two Indian millet crops.High yielding hybrid varieties of millet crops are resistant to pest attack and water stress.

Question. Enumerate four objectives for improving the nutritional quality of different crops for the health benefits of the human population by the process of “Biofortification”.
Answer. Biofortification is the breeding of crops with higher levels of vitamins and minerals or higher proteins and healthier fats, to improve the public health by practical means. Plant breeding is undertaken for improved nutritional quality of the plants with the objectives of improving :
– Protein content and quality
– Oil content and quality
– Vitamin content
– Micronutrient and mineral content.

Question. (a) Mention two ways of inducing artificial mutation in a crop plant.
(b) List two steps that help in introducing the desired mutation into the crop.
Answer.(a)In mutation breeding, mutations are induced artificially through the use of chemicals or radiations and plants having desired character are selected as a source in breeding. In mung bean, resistance to yellow mosaic virus and powdery mildew are introduced by mutation breeding.
(b) The steps in mutation breeding are :
(i) Inducing mutation through various mutagens/methods.
(ii) Screening the plant materials for disease resistance.
(iii) Multiplication for these selected plants for direct use or for use in breeding.
(iv) Hybridisation of the selected plant materials.
(v) Selection for disease resistance, testing and release as a variety.

Question. How has mutation breeding helped in improving the production of mung bean crop?
Answer. In mutation breeding, mutations are induced artificially through the use of chemicals or radiations and plants having desired character are selected as a source in breeding. In mung bean, resistance to yellow mosaic virus and powdery mildew are introduced by mutation breeding.

Question. Explain the advantage of cross breeding of the two species of sugarcane in India.
Answer. Saccharum barberi was originally grown in North India, but had poor sugar content and yield. However, Saccharum officinarum had higher sugar content and thicker stems but did not grow well in North India. These two species were crossed to have sugarcane varieties combining the desirable qualities of high sugar, high yield, thick stems and ability to grow in the sugarcane belt of North India.

Question. Enumerate, in sequential order, the 4 steps that a plant breeder should know to obtain a diseaseresistant crop. 
Answer.The various sequential steps are : screening germplasm for resistance sources, hybridisation of selected parents, selection and evaluation of hybrids and testing and release of new varieties

Question. Identify A, B, C and D in the following table.

Answer.In the given table :
A – Wheat
B – White rust
C – Pusa Shubhra, Pusa Snowball K-1
D – Cowpea

Question. Name the following:
(a) The semi – dwarf variety of wheat which is high yielding and disease resistant.
(b) Any one interspecific hybrid mammal.
Answer.(a) Sonalika and Kalyan Sona are semi-dwarf varieties of wheat, which are high yielding and disease resistant.
(b) Mule is an interspecific hybrid mammal, which is produced from a cross between female horse (mare) and male donkey.

Short Answer Type Questions

Question. How can crop varieties be made disease resistant to overcome food crisis in India? Explain. Name one disease resistant variety in India of:
(a) Wheat to leaf and stripe rust
(b) Brassica to white rust 
Answer. Breeding for disease resistant crop varieties is carried out by conventional breeding techniques or by mutation breeding. The conventional method of breeding for disease resistance is hybridisation and selection. The various sequential steps are: screening germplasm for resistance sources, hybridisation of selected parents, selection and evaluation of hybrids and testing and release of new varieties. Conventional breeding is often constrained by the availability of limited number of disease resistance genes that are present and identified in various crop varieties. Inducing mutations in plants sometimes leads to desirable genes being identified. Plants having these desirable characters can either be multiplied directly or can be used in breeding.
(a) Variety of wheat resistant to leaf and stripe rust – Himgiri
(b) Variety of Brassica resistant to white rust – Pusa Swarnim

Question. What is ‘biofortification’ ? Write its importance.Mention the contribution of Indian Agricultural Research Institute towards it with the help of two examples. 
Answer. Breeding of crops with higher levels of vitamins and minerals or higher proteins and healthier fats is called biofortification. This is the most practical aspect to improve the health of the people. Plant breeding is undertaken for improved nutritional quality of the plants with the objectives of improving :
– Protein content and quality
– Oil content and quality
– Vitamin content
– Micronutrient and mineral content.
Indian Agricultural Research Institute (IARI), New Delhi, has also developed many vegetable crops that are rich in minerals and vitamins. For example, vitamin A enriched carrots, pumpkin, spinach; vitamin C enriched bitter gourd, bathua, tomato; iron enriched spinach and bathua and protein enriched beans.

Question. What is autopolyploidy? How does colchicine induce polyploidy? Name an autopolyploid that has succeeded as a variety.
Answer. An organism which has more than two sets of chromosomes or genomes per cell is called polyploid and this condition is known as polyploidy. Autopolyploidy is a type of polypoidy in which there is a numerical increase of the same genome, e.g., autotriploid (AAA), autotetraploid (AAAA). Some of the crop and garden plants are autopolyploids, e.g., Maize, Rice Gram. Autopolyploidy induces gigas effect.
Polyploidy can be induced artificially by colchicine treatment. Colchicine is an alkaloid obtained from Colchicum autumnale. Colchicine prevents the spindle formation during mitotic cell division, so chromosomes do not pull apart during anaphase like they normally do thus inducing multiple sets of chromosomes. There are a few cases where an autopolyploid has succeeded as a variety e.g. an autotriploid variety of tea in India.

Long Answer Type Questions

Question. (a) What is plant breeding? List the two steps the classical plant breeding involves.
(b) How has the mutation breeding helped in improving crop varieties? Give one example where this technique has helped.
(c) How has the breeding programme helped in improving the public nutritional health?
State two examples in support of your answer.
Answer. 
(a) Plant breeding is an applied branch of botany which deals with the improvement of cultivated varieties (cultivars) of plants. It deals with the improvement in the heredity of crops and production of new crop varieties which are far better than original types in all respects. The main steps in production a new genetic variety of a crop are: evaluation and selection of parents and cross hybridisation among them. Testing, release and commercialisation of new cultivars are the other steps involved.
(b) It is possible to induce mutations artificially through use of chemicals or radiations (like gamma radiations), and selecting and using the plants that have the desirable character as a source in breeding. This process is called mutation breeding. Resistance to yellow mosaic virus and powdery mildew in mung bean were introduced by mutations.
(c) Breeding of crops with higher levels of vitamins and minerals or higher protein and healthier fats is called biofortification. This is the most practical aspect to improve the health of the people. Plant breeding is undertaken for improved nutritional quality of the plants with the objectives of improving :
– protein content and quality
– oil content and quality
– vitamin content
– micronutrient and mineral content.
Maize hybrids that had twice the amount of the amino acids–lysine and tryptophan, compared to existing maize hybrids were developed in 2000. Wheat variety with high protein content Atlas 66 has been used as a donor for improving cultivated wheat.

Question. With advancements in genetics, molecular biology and tissue culture, new traits have been incroporated into crop plants.Explain the main steps in breeding a new genetic variety of a crop. 
Answer.  Plant breeding is the purposeful manipulation of plant by crossing different varieties in order to create desired plant types that are better suited for cultivation, give better yields and are disease resistant.
Plant breeding involves the following steps :
(i) Collection of variability – Collection and preservation of all the different wild varieties, species and relatives of the cultivated species. The entire collection (of plant/seeds) having all the diverse alleles for all genes in a given crop is called germplasm collection.
(ii) Evaluation and selection of parents – The germplasm is evaluated so as to identify plants with desirable combination of characters.
(iii) Cross hybridisation among the selected parents- Hybridisation is crossing of two or more types of plants for bringing their traits together in the progeny. The procedure of hybridisation involves selection of parents with desired characters, selfing, emasculation, bagging, tagging and artificial pollination.
(iv) Selection and testing of superior recombinants – This is the selection of the plants, from the progeny of hybrids, which have the desired combined character. The selected plants are then self pollinated for several generations to get a uniformity i.e. homozygosity. Selection is of two types:
(a) Selection in selfpollinated crops – The degree of cross pollination is less than 5%. There is repeated self pollination of selected plants till superior homozygous genotypes are obtained. The best one is used as new variety. The self-pollinated progeny of homozygous plant constitutes a pure line.

(b) Selection in cross-pollinated crops – The crosspollinated crops are heterozygous for most of their genes and their population contains plants of several different genotypes. Superior genotype plants are selected and are allowed to crossbreed (these plants are not allowed to self breed) so that heterozygosity is also maintained.
(v) Testing, release and commercialisation of new cultivars– The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance etc. These selected cultivars are then tested with local best cultivar and are then released for commercialisation.