Outline6 marksChallenge
Outline the mechanism by which companion cells in plant leaves actively load sucrose into phloem sieve tubes, describing the roles of proton pumps and cotransporter proteins.
CAIE A Level Biology 9700 · Transport in plants
Transport in plants: outline question
How this question is marked
6 marks, so the mark scheme is looking for about 6 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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