Question: 93: In lac operon, z gene codes for :
(1) \beta-galactosidase
(2) Permease
(3) Repressor
(4) Transacetylase
Answer: Option (1)
Explanation:
The lac operon is a gene regulatory system in bacteria that controls the metabolism of lactose.
It consists of three structural genes: lac z, lac y, and lac a.
The lac z gene codes for the enzyme \beta-galactosidase,
which hydrolyses lactose into glucose and galactose.
The lac y gene codes for permease, which helps in the transport of lactose into the bacterial cell.
The lac a gene codes for transacetylase, which is involved in detoxification processes.
The repressor protein is not coded by the z gene but by a separate regulatory gene.
Therefore, in the lac operon, the z gene codes for \beta-galactosidase.