Improvement in Food Resources Test - 11

Local breeds of cattle are selected because of their excellent resistance to diseases.

Hence, the correct answer is option B.

Weeds are the unwanted plants in fields that compete with crop plants for water, nutrients, and light. Monoculture is an agricultural practice of growing single crop on a field. It promote the growth of weeds as a field of identical plants are more vulnerable to weeds, insect and disease.

Hence,the correct answer is option A.

Why alternatives A, B and D are wrong:

Crop rotation, application of weedicides and mechanical removal of weeds are methods used for controlling the growth of weeds in crop field.

Exotic breeds of cattle are selected because of their longer lactation period, which ensures high yield of milk.

The correct answer is A.

Why alternative B is wrong:

Shorter lactation period means less yield of milk. Exotic breeds of cattle are not selected for this trait.

Why alternatives C and D are wrong:

Exotic breeds of cattle are not selected on the basis of the duration of their life cycle.

Herbicides are chemicals used for controlling the growth of weeds. Therefore, herbicides cannot be used for reducing the damage to grains while in storage.

Hence, the correct answer is option B.

The fishes used in composite fish culture system have different food requirements. This ensures the use of all the food in the pond. It also helps avoid competition among fishes for food.

The correct answer is B.

Why alternatives A, C and D are wrong:

Local as well as imported fish species is used in composite fish culture.

Large feathers of the egg-laying bird will provide no commercial advantage in the poultry farming of egg-laying birds. Hence, this trait is not desirable for variety improvement in poultry.

The correct answer is A.

During variety improvement in poultry, dwarf broiler parent is desired for the commercial production of chicks.

Hence, the correct answer is option C.

Why alternative A is wrong:

Low maintenance requirement is a desirable trait for variety improvement in poultry.

Why alternative B is wrong:

High tolerance for high temperature during summers is a desired trait for variety improvement in poultry.

Why alternative D is wrong:

Small-sized egg-laying birds which can easily feed on cheap diet are desired for variety improvement in poultry.

Apis mellifera or Italian honey bees are most preferred for honey production as they give high yields of honey. These bees are sting less and they stay in their beehives for longer periods and breed well.

The correct answer is D.