Which process describes the buildup of pollutants within an individual organism over time?

• A. Bioaccumulation
• B. Biomagnification
• C. Biomes
• D. Aquatic ecosystem

Answer: (A)

Pollutants accumulate in an individual when the intake over time exceeds what the organism can eliminate or metabolize. This gradual buildup within one body is bioaccumulation. It happens as contaminants are taken in from water or food and stored in tissues (often fat), so ongoing exposure steadily increases the total body burden. Biomagnification, on the other hand, refers to contaminant levels rising as you move up the food chain from prey to predator, not within a single organism over time. Biomes are large regional ecosystems, and an aquatic ecosystem describes life in water, not the process of accumulation in one organism. So bioaccumulation is the correct concept.