Question

The biological amplification of DDT in the various trophic levels is known as
A. Greenhouse effect
B. Biomagnification
C. Eutrophication
D. Pollution

Answer 1

Hint: DDT stands for Dichlorodiphenyltrichloroethane. It was developed as the first artificial insecticide. It is a colourless, odourless compound which has severe environmental effects.

Complete Answer:
- The trophic level is the position of an organism in the food web. A food chain is a series of steps which shows the succession of organisms of eating other organisms and being eaten. Whatever one organism eats enters the food chain of the other organism.
- There are certain substances which cannot be degraded or broken by the environmental factors. For example DDT. It is indirectly consumed by the smaller organisms and enters the food chain. This process is called Biomagnification.

(I) Biomagnification is the process in which any concentration of toxin such as pesticides occurs in tissues of tolerant organisms at successively higher levels in a food chain.
(II) Greenhouse effect- By this effect the heat is trapped close to the surface of the earth.
(III) Eutrophication- It is the excessive growth of algae or other plants when the environment becomes rich in nutrients. For example excess algal growth in lakes and ponds.
(IV) Pollution- It is the addition of unwanted substances into the environment.

The correct answer is (B). The biological amplification of DDT in the various trophic levels is known as Biomagnification.

Note: The bioaccumulation like metals, pesticides are taken up by the organisms as they are very slowly metabolised and excreted. This can lead to severe disease conditions and even death.