Biology 5090 · O Level · Mineral nutrition

Mineral nutrition — practice question

Sweet clover is a plant from the pea and bean family (leguminous plants) that grows among grass in fields that are used as cattle feed.
(a)[2]

Explain how sweet clover may improve the soil where it grows.

(b)[1]

As sweet clover dries, fungi growing on it produce a chemical (dicoumarol) that prevents blood from clotting. Suggest a protein that cattle eating sweet clover affected by such fungi may be unable to produce.

(c(i))[2]

Describe the change in the $LD_{50}$ for dicoumarol in rats between 2000 and 2015.

(c(ii))[4]

Suggest an explanation for the change you described.

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