Q. The wild type E.coli cells are growing in normal medium with glucose. They are transferred to a medium containing only lactose as sugar. Which of the following changes take place?
A) The lac operon is induced.
B) E.coli cells stop dividing.
C) The lac operon is repressed.
D) All operons are induced.
Explanation
When E.coli bacteria are transferred to medium containing lactose, then the lac operon is induced. The lac operon consists of 3 structural gene (lac Z, lac Y and lac A). It involves the synthesis of β-galactosidase enzyme in E.coli, which hydrolyses lactose into glucose and galactose.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.