The Expression of the Lac Operon

Question

The expression of the lac operon
A) Must be initiated by the binding of an inducer protein
B) Involves the release of allolactose from a repressor protein
C) Does not involve the expression of structural genes
D) Necessitates the finding of RNA polymerase followed by transcription

Accepted Answer

The transcription of the lac operon is under negative control. Initiation depends on the binding of allolactose to a repressor protein. This reaction prevents the repressor from binding to the operator region, thus allowing RNA polymerase to bind and transcription to proceed.