Skip to content

Course home

Sign up

Cellular control

EasyMediumHard
12345678910111213141516
Question 6

The lac operon in Escherichia coli is a classic model of prokaryotic cellular control and gene regulation.

Which of the following statements regarding the components and regulation of the lac operon are correct?

  1. The regulatory gene (lacIlacIlacI) is structurally part of the lac operon and is transcribed from the same promoter as the structural genes.
  2. The binding of the inducer (allolactose) to the repressor protein alters its tertiary structure, preventing the repressor from binding to the operator.
  3. The structural gene lacY lacY\,lacY codes for the enzyme β\betaβ-galactosidase, which catalyses the hydrolysis of lactose into glucose and galactose.
A

1, 2 and 3

B

Only 1 and 2

C

Only 2 and 3

D

Only 2

Markscheme

Cellular control Questions

  1. A Level
  2. /Biology
  3. /Cellular control

30 exam-style questions on OCR A A Level Biology Cellular control. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank