Q. Which enzyme/s will be produced in a cell in which there is a nonsense mutation in the lac Y gene?
A) β-galactosidase
B) Lactose permease
C) Transacetylase
D) Lactose permease and transacetylase
Explanation
[Solution from source] The lac operon genes are transcribed in the order z, y, a. A nonsense mutation in lacY stops translation of permease, but β-galactosidase from lacZ, which lies upstream, is still made. Permease cannot be produced, and transacetylase downstream is lost or greatly reduced. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.