Biology 5090 · O Level · Effects of humans on ecosystems

Effects of humans on ecosystems — practice question

DDT is an insecticide and it is damaging to living organisms. Because it is not excreted, it accumulates inside the cells of living organisms. The diagram illustrates the route followed by DDT as it enters a lake. Dissolved in water 3 taken up by aquatic plants 3 eaten by herbivorous fish 3 eaten by carnivorous fish 3 eaten by fish-eating birds Which organisms would be harmed most by the DDT?

  • Aaquatic plants
  • Bcarnivorous fish
  • Cherbivorous fish
  • Dfish-eating birds

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