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The lac operon is composed of a regulatory gene (i gene) and three structural genes (z, y, and a). What does the i gene encode?

1. The i gene produces a repressor protein.
2. The z gene synthesizes beta-galactosidase.
3. The y gene generates permease enzyme.
4. The a gene is responsible for transacetylase production.

Correct answer: The i gene produces a repressor protein.

Solution

The i gene in the lac operon codes for the repressor protein, which regulates the operon by binding to the operator region and inhibiting transcription in the absence of an inducer.

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