NEST2025BiologyMolecular Basis of Inheritance
In the lac-operon system, lactose acts as an inducer that binds to the repressor protein attached to the operator region (lacO) and allows the expression of -galactosidase. When X-gal (a synthetic substrate) is added to the medium, -galactosidase converts it into a blue-coloured compound. In an experiment, the -galactosidase coding sequence was replaced with a T7RNA polymerase coding sequence downstream to the lac op
Options
- AIn the presence of both X-gal and lactose, but in the absence of factor Y, colonies will appear blue.
- BIn the presence of X-gal, lactose and factor Y, colonies will appear blue.
- CIn the absence of lactose, but in the presence of X-gal and factor Y , colonies will appear blue.
- DIn the absence of both lactose and factor Y , but in the presence of X-gal, colonies will appear blue.
Correct answer
A. In the presence of both X-gal and lactose, but in the absence of factor Y, colonies will appear blue.
Step-by-step solution
No Solution