Final answer:
Bioaccumulation is the process in which toxic substances, such as pesticides, accumulate in the bodies of organisms at each trophic level of a food chain.
Step-by-step explanation:
Bioaccumulation is the process in which toxic substances, such as pesticides, accumulate in the bodies of organisms at each trophic level of a food chain. It means that the concentration of these substances becomes higher as you move up the food chain.
For example, when pesticides are sprayed on crops, the plants absorb some of the pesticides. Then, herbivorous animals that eat these plants consume the pesticides as well. When carnivorous animals eat these herbivores, they accumulate an even higher concentration of the pesticides. Hence, in an ecosystem, the last animals in the food chain, such as top predators, tend to have the highest levels of pesticide accumulation.