Question

Lac operon is called negative regulation because__________

• A. the repressor protein inhibits the transcription of structural genes.
• B. it gets active only in presence of lactose
• C. the structural genes can digest lactose
• D. both b and c

Answer 1

The correct option is A the repressor protein inhibits the transcription of structural genes.

In lac operon, the inhibitor gene codes for a repressor protein which binds with the operator gene and restricts the transcription of structural genes.

As lac operon is regulated by a repressor protein, it is an example of negative regulation.