Question

To inhibit the transcription of operon genes, the lacl gene product binds to

a. the inducer
b. the promoter
c. the operator
d. the lacZ gene
e. the repressor

Answer 1

The repressor protein binds to the operator to inhibit transcription of operon genes.

Step-by-step explanation:

The correct answer is e. the repressor. The lac operon is a genetic system found in bacteria, specifically E. coli, that consists of regulatory regions and structural genes. The repressor protein, encoded by the lacl gene, binds to the operator sequence on the DNA, preventing RNA polymerase from transcribing the structural genes of the lac operon. This inhibition of transcription stops the production of enzymes involved in lactose metabolism.