Question

Gene regulation governing lactose operon of E.coli that involves the lac-I gene products is?

• A. Negatively and repressible because repressor protein prevents transcription
• B. Feedback inhibition because excess of $\beta$-galactosidase can switch off transcription
• C. Positive and inducible because it can be induced by lactose
• D. Negative and inducible because repressor protein prevents transcription

Answer 1

The correct option is A Negatively and repressible because repressor protein prevents transcription

Lac I gene generates a lac operon inhibitor or rerpressor and is caused by negative regulation. The repressor connects to the gene of the operator and prevents its operation. Repressor is intended to block the gene of the operator in order to prevent structural genes from forming -mRNA thus stopping gene transcription.