Question

Cause of decline in population of reptiles and birds is

• A. Bioinsecticides
• B. Biofetilizers
• C. DDT
• D. Both A and B

Answer 1

The correct option is C DDT

A. Bioinsecticides are the biological agents or organisms that are used to control pests.

B. Biofertilizers are the microorganisms that are used to supply nutrients in the soil and increase its fertility.

C. Dichlorodiphenyltrichloroethane or DDT is a crystalline, colourless and odourless compound which is used as an insecticide. DDT on runoff from the fields reach the water bodies and gets accumulated in the bodies of fishes. When fishes are eaten by birds, it gets accumulated in the body of birds and hence, in this way it enters the food chain. With each successive trophic level, concentration of DDT increases and this is known as biomagnification.

High concentration of DDT disturbs the calcium metabolism of birds and reptiles and causes thinning of egg shells. and premature breaking. This leads to decline in their population.

So, the correct answer is 'DDT'.