What term describes the increase in contaminant concentration as it moves up the food chain?

• A. Biomagnification
• B. Bioaccumulation
• C. Adsorption
• D. Photolysis

Answer: (A)

The concept tested is how contaminants can become more concentrated as you move up the food chain. This happens when organisms at higher trophic levels accumulate chemicals by eating prey that already contain them, and because the substances are persistent and not easily eliminated, their concentrations rise with each step up the chain. Top predators can end up with much higher levels than the organisms they feed on.

This upward transfer and concentration is known as biomagnification. It specifically describes the increase in contaminant concentration from one trophic level to the next. By contrast, bioaccumulation refers to buildup within a single organism from its environment or diet, not the transfer across multiple levels of the food chain. Adsorption is the sticking of a chemical to surfaces like soil or sediment, which is not about moving through organisms. Photolysis is the breakdown of chemicals by light, which reduces concentration rather than increasing it.