Question

From their experiments, Jacob and Monod found that, in the absence of lactose, a lactose repressor will bind to a(n) ________.

A) Operator
B) Promoter
C) Enhancer
D) Exon

Answer 1

In the absence of lactose, the lactose repressor binds to the operator region of the lac operon, preventing RNA polymerase from transcribing the structural genes.

Step-by-step explanation:

In the absence of lactose, a lactose repressor will bind to the operator region of the lac operon. The operator is a DNA sequence located between the promoter and the structural genes in the operon. The binding of the repressor protein to the operator physically blocks the movement of RNA polymerase, preventing the transcription of the structural genes.