In a lake, a pesticide that cannot be broken down is found in water at 0.0001 ppm, in plankton at 0.01 ppm, in small fish at 0.5 ppm and in fish-eating birds at 25 ppm. Which process explains the rising concentration?
Answer and explanation
Correct answer: A. Bioaccumulation and biomagnification
- Step 1: The concentration rises at every step up the food chain. Step 2. A substance that is not broken down or excreted is stored in tissues, and predators eat many prey, so they receive more of it. Answer: biomagnification. Why not the others: Photosynthesis does not make pesticides, decomposition would lower the concentration, and nitrogen fixation concerns nitrogen compounds.
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