Which of the following switches off lac operon?

Options

AStructural gene
BRegulator gene
COperator gene
DPromoter gene

Correct answer

B. Regulator gene

Step-by-step solution

Regulator gene codes for a protein known as repressor protein. The operon is switched off when repressor protein produced by regulator or inhibitor gene binds to operator gene and prevents RNA polymerase from transcribing the operon.

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