Q. Which enzyme will be produced in a cell if there is a non-sense mutation in the lac Y gene of lac operon?
A) b-Galactosidase
B) Lactose permease
C) Transacetylase
D) Transferase
Explanation
Lac Y gene encodes permease enzyme. Due to nonsense mutation in it, permease will not be formed and only b-galactosidase enzyme will be formed by lac Z gene because of the addition of a stop codon in the lac operon after lac Z gene. The arrangement of genes in lac operon is as follows: [image:6_image97.wmf]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.