Question

In a lake contaminated with pesticides, which one of the following organism living in the lake will contain the maximum amount of pesticide?
Small fish, zooplankton, big fish, phytoplankton.

Answer 1

The concentration of pesticide will increase with the rise of trophic level in the food chain.
Phytoplankton -----> Zooplankton ---> Small fish
-----> Big fish (maximum pesticide) 

Therefore, big fishes will have maximum amount of pesticides.