What term refers to the increase in toxin concentration as you move up the food chain?

• A. Energy pyramid
• B. Number pyramid
• C. Keystone predator
• D. Biological magnification

Answer: (D)

Biomagnification, or biological magnification, is the idea that toxin levels increase as you move up a food chain. Toxins accumulate in organisms over time (bioaccumulation), and when a predator eats contaminated prey, it takes in all the toxins contained in those prey. Because many contaminants are fat‑soluble and persistent, they aren’t easily broken down or excreted, so concentrations get higher at higher trophic levels. That’s why top predators end up with much higher toxin levels than organisms at the bottom. In contrast, energy pyramids and number pyramids describe how energy or population numbers transfer across levels, not toxin concentration, and a keystone predator is about a species’ ecological role, not toxin buildup.