iGCSE Biology (0610)-20.3 Pollution – iGCSE Style Questions Paper 2

Question

The flow diagram shows a process that can occur as a result of pollution in a river.

     

Which term describes the process shown in the flow diagram?
A aerobic respiration
B eutrophication
C nitrogen cycle
D photosynthesis

Answer/Explanation

Ans

B

Question

Which stage in the treatment of sewage removes large floating objects, such as plastic bags?
      A aeration
      B discharge
      C screening
      D sedimentation

Answer/Explanation

Ans

C

Question

The diagram shows the positions of four farms and the concentrations of nitrate at different points
in a river.
Which farm is likely to have been using too much fertiliser on its land?

Answer/Explanation

Ans: A

Question

When nitrates enter a lake they cause rapid growth of algae on the surface of the water. This causes the following changes in the lake:

1   a decrease in the concentration of dissolved oxygen in the water
2   fish and other aquatic animals die
3   an increase in aerobic respiration by decomposers
4   producers die and decomposition increases

In which order do these changes occur?

A    1 → 2 → 4 → 3
B    3 → 1 → 2 → 4
C    4 → 2 → 3 → 1
D    4 → 3 → 1 → 2

Answer/Explanation

Ans:    D

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