Question

If a harmful chemical enters a food chain comprising snakes. hawks. mice and plants. Which of these organisms is likely to have maximum concentration of the harmful chemicals in its body?

Answer 1

Hint: A food chain is a linear chain which represents the transfer of energy in the form of food from one organism to another. As the trophic level increases the net energy reduces and the accumulation of toxins increases. At the highest trophic level, the organisms have least energy and maximum biomagnification.

Complete answer:
The food chain begins with the producers or the autotrophs followed by the primary(herbivores) and secondary consumers (carnivores) and ends with the decomposers. In the given question the food chain is represented as:
                                               Plants -> Mice -> Snakes -> Hawks

Where plants are the producers, mice are the primary consumer, snake and hawks are the secondary and tertiary consumers respectively.
If any harmful chemical or toxin is consumed by the organism and it enters the food chain then it is passed on from one trophic level to the other. This is known as biomagnification.

Biomagnification is the process by which the toxins are built up within organisms and the maximum build up takes place in the larger species or the animals occupying the highest trophic level in the food chain. This is due to larger animals eating up smaller ones.
So, with respect to the food chain in the given question, the maximum accumulation of the toxins is found in Hawk as it occupies the highest trophic level.

Note: Biomagnification takes place when the toxin or the harmful substance is non-biodegradable in nature. Biomagnifications leads to the toxicological effects and further decline in the organisms occupying higher levels. For example-metals are the bioaccumulations which are non-biodegradable and cause toxic effects.