Question

Which is the correct pair of biological magnification?
A) Water- 0.0003 ppm
B) Small fishes- 0.2 ppm
C) Big fishes- 2 ppm
D) Zoo plaktery- 0.4 ppm

Answer 1

Hint: Biological magnification is also known as biomagnification or bioamplification. Biological magnification is related to an increase in the concentration of certain toxins which are absorbed by the tissues of tolerable organisms along the food chain.

Complete answer:
Biological magnification is the process by which concentration of certain toxins, chemicals or pesticides is increased at each trophic level of food chain. The correct order of the food chain given in this question is:
Water $\rightarrow$ Zoo plakater $\rightarrow$ Small fishes $\rightarrow$ Big fishes

So, according to this food chain, the concentration of toxin or chemicals will increase at each trophic level from water to big fishes. There is an increase in the concentration of toxins or chemicals from 2 to 10 folds at each increasing trophic level. The concentration of toxin or chemicals in water is very low (0.0003 ppm) which can’t be considered. The concentration in small fishes (0.2 ppm) is less than zoo plaktery (0.4 ppm) which is wrong. Ideally, it must be greater in small fishes as compared to zoo plaktery. Hence, options (A), (B) and (D) are incorrect. The concentration of toxin or chemicals in big fishes is the highest (2 ppm).

Hence, the correct answer is option (C).

Note: Biomagnification is known for the increase in concentration of certain toxins or chemicals along the food chain. The concentration increases about 2 to 10 folds at each trophic level. The concentration of toxins such as pesticides or chemicals increases at each trophic level of the food chain indicating that the highest trophic level will possess the greatest concentration of the toxin.