CAIE A Level Biology 9700 · Inheritance
In a bacterial species, the enzymes for lactose metabolism (β-galactosidase and permease) are produced when lactose is present in the growth medium, but not when lactose is absent.
(a) Outline the genetic control of enzyme production in this bacterium, using the lac operon as an example.
(b) Outline how the plant hormone gibberellin activates genes in plant cells.
5 marks, so the mark scheme is looking for about 5 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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