CAIE A Level Biology 9700 · Inheritance
In a study of stem elongation in a plant species, researchers identified a mutant that lacks the DELLA protein. This mutant shows continuous stem elongation even in the absence of gibberellin.
Outline the mechanism by which gibberellin normally activates genes involved in stem elongation, including the role of DELLA proteins.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Outline means: Give the main points briefly. Less detail than describe, but every key step has to be there. One short line per step, in order. The marks are for coverage, not depth.
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