NEET Biology Strategies for Enhancement in Food Production MCQs Set 19

Answer: (b) Progeny plants with superior characters are self-pollinated for several generations till they reach a state of heterozygosity

Explanation:
1. Progeny plants with superior characters (hybrid vigour) are self-pollinated for several generations till they reach a state of homozygosity (do not segregate).
2. Hence option (b) is correct: Progeny plants with superior characters are self-pollinated for several generations till they reach a state of heterozygosity

Teacher's Note:
1. Homozygosity, not heterozygosity, is the aim of repeated self-pollination.
2. Once the plants no longer segregate, the line is true breeding and can be tested.

Answer: (a) High protein content

Explanation:
1. Atlas 66 variety of wheat was developed for high protein content.
2. Hence option (a) is correct: High protein content

Teacher's Note:
1. Atlas 66 is a high-protein wheat variety.
2. It was used as a donor of high protein content in breeding programmes.

Answer: (c) National Bureau of Plant Genetic Resources

Explanation:
1. A government agency which keeps control on introduction of new variety of plants in India is National Bureau of Plant Genetic Resouces (NBPGR).
2. Hence option (c) is correct: National Bureau of Plant Genetic Resources

Teacher's Note:
1. NBPGR, New Delhi, handles plant introduction and quarantine of germplasm in India.
2. Imported varieties must be cleared by it first.

Answer: (c) Somatic embryogenesis

Explanation:
1. Development of embryo like structure from explant through tissue culture method is called somatic embryogenesis.
2. Hence option (c) is correct: Somatic embryogenesis

Teacher's Note:
1. Micropropagation means producing many plants from small plant parts in tissue culture.
2. Somatic embryogenesis, where embryos form from somatic cells, is one such technique.

Answer: (c) Polyethylene glycol and sodium nitrate

Explanation:
1. Polyethylene glycol and sodium nitrate enhance or induce fusion of protoplasts.
2. Hence option (c) is correct: Polyethylene glycol and sodium nitrate

Teacher's Note:
1. Protoplast fusion needs a fusogen such as polyethylene glycol (PEG) or sodium nitrate.
2. Hormones like IAA and kinetin only control growth, not fusion.

Answer: (a) Meristem

Explanation:
1. Meristems are virus free parts of plants.
2. Hence option (a) is correct: Meristem

Teacher's Note:
1. Meristem tips are usually free of viruses because virus spreads poorly in dividing cells.
2. This is why virus-free plants are raised from them.

Answer: (a) Gamma radiations

Explanation:
1. Gamma radiation is a high-energy radiation that can change the DNA of seeds.
2. Infra-red radiation, IAA and ethylene do not cause mutations.
3. Hence option (a) is correct: Gamma radiations

Teacher's Note:
1. Mutagens such as gamma rays and chemicals induce mutations.
2. IAA and ethylene are plant hormones, and infra-red radiation is not a mutagen.

Answer: (a) Wheat

Explanation:
1. Himgiri is a wheat variety developed by hybridisation and selection for resistance to leaf and stripe rust.
2. Hence option (a) is correct: Wheat

Teacher's Note:
1. Himgiri is a wheat variety resistant to leaf and stripe rust.
2. It was developed by hybridisation and selection.

Answer: (c) Germplasm

Explanation:
1. Diverse alleles of all the genes of a crop is called germplasm.
2. Hence option (c) is correct: Germplasm

Teacher's Note:
1. Germplasm collection is a store of all alleles of a crop.
2. A herbarium holds preserved plant specimens, not living alleles.

Answer: (a) Zea mays

Explanation:
1. Bioethanol is produced by fermenting starch or sugar crops, and maize (Zea mays) is a standard source.
2. Jatropha, Pongamia and Brassica are oil plants used for biodiesel.
3. Hence option (a) is correct: Zea mays

Teacher's Note:
1. Bioethanol is made by fermenting sugars from starch or sugar crops such as maize and sugarcane.
2. Pongamia and Jatropha give biodiesel, and Brassica gives oil.

Answer: (d) Tissue culture

Explanation:
1. Somaclones are genetically identical plants derived from a single plant by tissue culture.
2. Hence option (d) is correct: Tissue culture

Teacher's Note:
1. Somaclones are plants produced by tissue culture from somatic cells.
2. They are genetically identical to the parent unless somaclonal variation occurs.

Answer: (d) (c) and (d)

Explanation:
1. Bacterial blight is seed borne, so disease-free seeds help, and resistant varieties give lasting protection.
2. Bordeaux mixture is a fungicide and the vector control does not apply to a seed-borne bacterium.
3. Hence option (d) is correct: (c) and (d)

Teacher's Note:
1. The disease can be controlled by sowing disease-free seeds and by growing resistant varieties.
2. Bordeaux mixture is used against fungal diseases, not bacterial blight.

Answer: (b) Crossing of two inbreed parental lines

Explanation:
1. Hybrid vigour (heterosis) is obtained by crossing two different inbred parental lines.
2. The F1 hybrid is superior to both parents.
3. Hence option (b) is correct: Crossing of two inbreed parental lines

Teacher's Note:
1. Hybrid vigour in maize is exploited by crossing two inbred lines.
2. The seed from the cross is then sown by the farmer every year.

Answer: (a) Wheat, rice and maize

Explanation:
1. Wheat, rice and maize contribute the most to global food-grain production.
2. Hence option (a) is correct: Wheat, rice and maize

Teacher's Note:
1. The three cereals with the highest world production are wheat, rice and maize.
2. Barley and sorghum are produced in smaller amounts.

Answer: (a) Preparation of pure cellulose by removing lignin

Explanation:
1. In pulp making, lignin is removed from woody tissue by chemical treatment to leave pure cellulose fibres.
2. Hence option (a) is correct: Preparation of pure cellulose by removing lignin

Teacher's Note:
1. Paper pulp is made from cellulose, so lignin must be removed from the wood.
2. Lignin makes the pulp coloured and weak.

Answer: (d) Gamma rays (from cobalt 60)

Explanation:
1. Gamma rays from cobalt 60 is used to induce mutation.
2. Hence option (d) is correct: Gamma rays (from cobalt 60)

Teacher's Note:
1. Gamma rays from cobalt-60 are the usual mutagen for crop plants.
2. Alpha particles and UV rays penetrate poorly.