Sponsor Area

Molecular Basis Of Inheritance

Question
CBSEENBI12047495

Select the correct statements out of the four (I-IV) given below about lac operon.

I. Glucose or galactose may bind with the repressor and inactivate it.

II. In the absence of lactose, the repressor binds with the operator region.

III. The Z-gene codes for permease.

IV. This was elucidated by Francois Jacob and Jacques Monad.

The correct statements are

  • II and III

  • I and III

  • II and IV

  • I and II

Solution

C.

II and IV

Lac operon was elucidated by Francois Jacob and Jacques Monod. It is an operon required for the transport and metabolism of lactose in E. coli and many other enteric bacteria.

In lac operon lactose or allolactose binds with the repressor and induces the lac operon system. In the absence of lactose, the repressor binds with the operator region and the Z-genes in this codes for β- galactosidase.