NEET Zoology Question (2026) — Solution

Step-by-step solution

In the lac operon, the structural genes are z, y, and a. The z gene codes for beta-galactosidase, which is primarily responsible for the hydrolysis of the disaccharide lactose into its monomeric units, galactose and glucose. The y gene codes for permease, which increases permeability of the cell to beta-galactosides. The a gene codes for a transacetylase. The i gene codes for the repressor of the lac operon. Answer: beta-galactosidase