(a(i))[3]
Give the key features of the $lac$ operon.
(a(ii))[4]
Explain the function of the $lacI$ gene in regulating the $lac$ operon.
(b)[3]
Suggest and explain why a repressible operon is beneficial to a prokaryote.
Biology 9700 · AS & A Level · Gene control
Gene control — practice question
Gene expression inside a cell is regulated. If a gene is expressed (switched on), transcription of that gene occurs. If a gene is not expressed (switched off), transcription does not take place. Environmental changes can lead certain genes to be turned on or turned off.