The wild-type E. coli cells are growing in a normal medium with glucose. They are transferred to a medium containing only lactose as sugar. Which of the following changes takes place?
Correct answer: A. The lac operon is induce
- A. The lac operon is induce
- 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 a medium containing lactose, the lac operon is induced. The lac operon consists of 3 structural genes (lac Z, lac Y, and lac A). It involves the synthesis of the b-galactosidase enzyme in E.coli, which hydrolyses lactose into glucose and galactose.
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