CAIE A Level Biology 9700 · Inheritance
In prokaryotes, the lac operon controls the production of enzymes for lactose metabolism. In eukaryotes, plant stem elongation is promoted by gibberellin, which acts by causing breakdown of DELLA repressor proteins.
Outline the differences between structural genes and regulatory genes, and between repressible and inducible enzymes, using the lac operon and the gibberellin-DELLA system as examples.
7 marks, so the mark scheme is looking for about 7 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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