What is biological magnification?

Question

alsoo, which organisms in a typical food chain would have the greatest concentration of toxin?

Answer 1

Each time  organism's at one level are eaten by an organisms  at a higher level , the concentration of toxic material increase. this is because each level must eat mass of about 10 times its own  mass to provide enough energy to live. . This phenomenon is called bioilocal magnification

Answer 2

If the substance isn't excreted, it buids up with each step up the food chain. Thus, the apex predator would have the highest concentration. For example, seals eat fish and concentrate the vitamin A from their livers. Polar bears eat seals and the concentration of vitamin A in THEIR livers is high enough to be toxic.