Which term describes the buildup of chemicals in tissues over time, especially as you consider higher trophic levels?

• A. Biodegradation
• B. Biomagnification
• C. Bioaccumulation
• D. Bioremediation

Answer: (C)

Think about how pollutants move through ecosystems. Bioaccumulation is the buildup of a substance inside a single organism over time, from all the sources it encounters. Biomagnification, on the other hand, describes how the concentration of a contaminant increases as you move up the food chain, from prey to predator. When a question highlights higher trophic levels, it’s pointing to biomagnification, because top predators can accumulate much higher levels of a contaminant by eating many contaminated prey. For example, mercury or certain pesticides can become much more concentrated in large fish, then in birds that eat those fish, and so on. Biodegradation and bioremediation involve breaking down or removing pollutants, not the pattern of increasing concentration across predators. So the best concept for the described buildup across trophic levels is biomagnification.