NEET Biology Strategies for Enhancement in Food Production MCQs Set 15

Answer: (d) phytoalexins

Explanation:
1. Phytoalexins are produced by plants that are under attack.
2. Phytoalexins produced in plants act as toxins to the attacking organism.
3. Hence option (d) is correct: phytoalexins

Teacher's Note:
1. They may puncture the cell wall, delay maturation, disrupt metabolism or prevent reproduction of the pathogen in question.
2. However, phytoalexins are often targeted to specific predators; a plant that has anti-insect phytoalexins may not have the ability to repel a fungal attack.

Answer: (a) length

Explanation:
1. Auxanometer is an apparatus for measuring increase or rate of growth in plants.
2. It automatically detects and measures plant growth and stores information in a data logger.
3. Hence option (a) is correct: length

Teacher's Note:
1. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (a) soil fertility

Explanation:
1. Crop rotation increases the soil fertility by sowing different crops, usually legume and non-legume, in successive seasons on the same piece of land.
2. Hence option (a) is correct: soil fertility

Teacher's Note:
1. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.
2. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.

Answer: (a) pollen grains

Explanation:
1. Pollen grains are used for haploid cultures since they possess n-number of chromosomes that are required for haploid cultures.
2. Hence option (a) is correct: pollen grains

Teacher's Note:
1. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (c) has association of nitrogen-fixing Cyanobacteria

Explanation:
1. Azolla, has cyanobacteria which is the nitrogen fixing bacteria.
2. Due to this Azolla is able to fix the nitrogen as nitrates, thereby making it available to plants in the soluble form of nitrogen.
3. Hence option (c) is correct: has association of nitrogen-fixing Cyanobacteria

Teacher's Note:
1. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.
2. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.

Answer: (c) tissue culture

Explanation:
1. Somaclonal variations are differences in plants that are raised from the callus by tissue culture.
2. If these variations are of economic value, e.g. , induce tolerance of pests, diseases, etc, such plants are selected and multiplied.
3. Hence option (c) is correct: tissue culture

Teacher's Note:
1. This technique has been used in wheat, rice, potato and tomato.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (b) scion

Explanation:
1. The quality of fruits produced by the grafted plant is determined by the genotype of scion.
2. Hence option (b) is correct: scion

Teacher's Note:
1. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (c) Seeds

Explanation:
1. Cocoa is obtained from seeds of cocoa plant Theobroma.
2. It belongs to family sterculiaceae.
3. Hence option (c) is correct: Seeds

Teacher's Note:
1. This plant is a native of tropical America and its seeds are used to prepare cocoa and chocolate.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (a) unequal distribution of auxin in the stem.

Explanation:
1. The plant hormone, auxin, is more distributed on the side away from the unilateral illumination causing cells to grow faster in the darkerside, which in turn, causes the plant to bend toward the light.
2. If the distribution were equal, the plant would grow just upwards.
3. Hence option (a) is correct: unequal distribution of auxin in the stem.

Teacher's Note:
1. Neuro-transmitters are chemicals secreted by multicellular animals and are used in transmitting impulses in the nervous system.
2. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.

Answer: (c) grow plants under controlled conditions.

Explanation:
1. Phytotron is a chamber in which plants can be grown in controlled condition.
2. Hence option (c) is correct: grow plants under controlled conditions.

Teacher's Note:
1. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.
2. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.

Answer: (d) cytokinin

Explanation:
1. Coconut water is rich in cytokinin.
2. Cytokinin initiates cell division and is found in dividing tissues.
3. Hence option (d) is correct: cytokinin

Teacher's Note:
1. So, coconut water is used as a medium in tissue culture of plant tissues where it initiates cell division.
2. Coconut water is liquid endosperm.

Answer: (d) Cross breeding

Explanation:
1. Hisardale is a new breed of sheep developed in Punjab by crossing Bikaneri ewes and Marino rams.
2. Cross breeding is a method in which superior male of one breed is mated with superior females of another breed.
3. Hence option (d) is correct: Cross breeding

Teacher's Note:
1. It allows the desirable qualities of two different breeds to be combined.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (c) clorax or hypochlorite

Explanation:
1. Before transferring on the culture medium, the explant is first of all disinfected by surface sterilization using clorax water, sodium or calcium hypochlorite solution or methiolate.
2. Too much care must be taken in this operation so that the cells do not die.
3. Hence option (c) is correct: clorax or hypochlorite

Teacher's Note:
1. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.
2. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Any living plant cell which is viable can be used to culture somatic embryos.
2. These embryos have the characteristic features of the parent plant.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. The somatic cultures are viable from the stem, root or leaves and the most viable part is the meristematic cell.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Irrigation relates to the supply of water to the crops.
2. Fertilizers which are mainly NPK are required to increase the harvest of crops.
3. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. Food production questions combine breeding methods, tissue culture and biofertilisers, so keep one example for each.
2. Learn the full forms and uses of terms such as somaclonal variation, explant and phytotron.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Superovulation is done by hormone injection.
2. During artificial insemination, 4-10 embryos are transplanted into carrier cows.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. The seven days old embryos can be preserved at a temperature of –196ºC for several years.
2. The assertion & reason are true and the reason is the correct explanation for the assertion.