Question

In lac operon system, lac i gene codes for :-

• A. Inducer
• B. Repressor
• C. Promoter
• D. β-galactosidase

Answer 1

The correct option is B

Repressor

The correct answer is option B.

Explanation of the correct option:

1. Lac i gene also called regulator gene.
2. They are responsible for the production of a specific protein called repressor which binds to the operator gene.
3. It causes suppression of synthesis of mRNA from operator gene.

Explanation of the incorrect options:-

Option A

Inducer prevents the function of repressor protein. Lactose is a common inducer.

Option C

A promoter is a binding site for the RNA Polymerase enzyme.

Option D

β-galactosidase is an enzyme that converts Lactose into Glucose and Galactose.

Final answer: In the lac operon system, the lac i gene codes for repressor.