CAIE A Level Biology 9700 · Inheritance
Table 1 shows the relative activity of β-galactosidase in cultures of E. coli grown in the presence and absence of lactose.
| Growth condition | Relative β-galactosidase activity |
|---|---|
| without lactose | 0 |
| with lactose | 100 |
Outline how the lac operon controls the production of β-galactosidase in E. coli. In your answer, refer to the roles of structural genes and regulatory genes.
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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