A mutation in the gene encoding the lactose repressor (lacI) that prevents lactose from binding to the LacI protein would result in
A) constant expression of the lac operon in the absence of lactose.
B) constant repression of the lac operon in the absence of lactose.
C) constant expression of the lac operon in the presence of lactose.
D) constant repression of the lac operon in the presence of lactose.

Question

Quizplus · Accepted Answer

If lactose cannot bind to the LacI repressor, the repressor will not be removed from the operator, leading to constant repression of the lac operon even when lactose is present.

A Mutation in the Gene Encoding the Lactose Repressor (LacI)