Question

In the 'Lac operon system', galactosidase is coded by which gene?

• A. A gene
• B. I gene
• C. O gene
• D. Y gene
• E. Z gene

Answer 1

Answer: (E)

Z gene

The lac operon is an operon required for the transport and metaboilsm of lactose in E.coli and some other enteric bacteria. It has three adjacent structural genes, lac Z, lac Y and lac A. The genes encode $\beta$-galactosidase, lactose permease and thio-galactoside transacetylase, respectively.