Biomagnification shows up on the APES exam almost every year—and students often miss the math and the “why.” This AP Environmental Science activity fixes both. Students complete progressively rigorous toxin calculations through real food chains (DDT + mercury), calculate bioaccumulation factors (BAF), analyze a graph showing exponential increase, and finish with AP-style FRQ practice plus real-world policy evaluation (DDT ban, Minamata disease, mercury advisories, PCB cleanup). ✅ Mirrors t