Q. In an $E.\ coli$ strain $i$ gene gets mutated and its product can not bind the inducer molecule. If growth medium is provided with lactose, what will be the outcome?
A) RNA polymerase will bind the promoter region
B) Only $z$ gene will get transcribed
C) $z, y, a$ genes will be transcribed
D) $z, y, a$ genes will not be translated
Explanation
[Solution] The repressor cannot bind the inducer, so it stays bound to the operator; the $z, y, a$ genes are not transcribed and hence not translated. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.