Biology 9700 · AS & A Level · Testing for biological molecules

Testing for biological molecules — practice question

Fig. 3.1 depicts part of the nitrogen cycle.
(a(i))[3]

Name the processes labelled A, B and C.

(a(ii))[3]

Dead plant and animal remains may also add to the pool of inorganic nitrogen in soil. Describe how this occurs.

(b(i))[2]

State one role of phosphate and one role of nitrate in organisms.

(b(ii))[3]

Nitrogen and phosphate both cycle faster in ecosystems with high rates of growth within trophic levels and high rates of energy flow between trophic levels. With reference to how both nitrogen and phosphate are used in organisms, explain this statement.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: A corresponds to denitrification/reduction

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