How does the lactose repressor block transcription of the lactose operon?

A) by "turning off" the lacA intron
B) by degrading the lacZ protein product
C) by binding allosterically to the lacZ gene
D) by slowing the uptake of lactose into the cell
E) by binding to the operator

Lactose Repressor

The lactose repressor is a protein that binds to the promoter region of the lactose operon in bacteria, regulating the metabolism of lactose by inhibiting the transcription of lactose-utilizing genes.

Transcription

The process in which the DNA sequence in a gene is copied into mRNA, serving as the first step in gene expression.

Lactose Operon

A gene regulatory mechanism in bacteria that allows the cells to adapt to the presence of lactose, enabling the digestion of this sugar when it is available.