(a(i))[1]
State which type of microorganism contains chlorophyll.
(a(ii))[2]
From this information and Fig. 5.3, calculate the total mass of chlorophyll in the sample on day 1. Remember to include units in your answer.
(a(iii))[1]
Suggest why the researchers measured chlorophyll concentration instead of counting the microorganisms in the sample.
(a(iv))[1]
Using Fig. 5.3, identify the day on which the water was clearest.
(a(v))[2]
Explain why water transparency matters for organisms that contain chlorophyll.
(b(i))[1]
State which ions could lead to a rise in the number of organisms in the lake that contain chlorophyll.
(b(ii))[3]
Explain what the death of these organisms would do to the lake ecosystem.
(c)[5]
Outline how sewage should be treated so that the resulting water is safe to release into the lake.