Question

31- Explain why the number of trophic levels in a community is limited.

32- Explain the link between food webs and biomagnification.

33- Describe and diagram the four primary biogeochemical cycles.

34- Explain factors that affect biodiversity.

35- Explain how water and air pollution affect biodiversity.

36- Explain how exotic species can affect biodiversity.

Answer 1

31- The trophic levels numbers in a community is limited because the energy available to each level is only 10% of the energy that the lower level has available to it. subsequently in the third consumer there is not that much energy remains

32- Biological magnification refers to the process where by some substances such as heavy metals or pesticides move up the food chain, work their way into rivers , and been eaten up by aquatic organisms such as fish, which in turn are eaten by humans or animal .

for example : An eats zoo-plankton that have small amounts of mercury that zoo-plankton has picked up from the H₂O throughout the anchovies lifespan. many of these anchovies are eaten up by tuna over its life, gathering the mercury in each of those anchovies into its body. If the mercury stops the growth of the anchovies,then that tuna is required to eat more little fish to stay alive.since, Because there are more little fish being eaten, the mercury content is enlarged.