Question

In Escherichia coli, lac operon is induced by

• A. Lactose
• B. Promoter gene
• C. Beta - galactosidase
• D. I-gene

Answer 1

The correct option is A Lactose

A. Lactose

Solution: lac operon in E. coli is an operon which contains genes involved in lactose metabolism. But this operon is turned "on" only when there is lactose present in the medium. In the absence of lactose, lac operon remains turned "off''.

So the correct answer is "Lactose."