NEET2025Zoology-Recombinant DNA Technology

NEET 2025 Zoology Blue-White Screening Assertion Reason Question

Type: Assertion Reason-conceptual-Medium-Class 12

The blue and white selectable markers have been developed which differentiate recombinant colonies from non-recombinant colonies on the basis of their ability to produce colour in the presence of a chromogenic substrate.

Given below are two statements about this method:

Statement I : The blue coloured colonies have DNA insert in the plasmid and they are identified as recombinant colonies.

Statement II : The colonies without blue colour have DNA insert in the plasmid and are identified as recombinant colonies.

In the light of the above statements, choose the most appropriate answer from the options given below :

A

Both Statement I and Statement II are correct

B

Both Statement I and Statement II are incorrect

C

Statement I is correct but Statement II is incorrect

D

Statement I is incorrect but Statement II is correct

Correct Answer

Option D

Detailed Explanation

In blue-white screening, recombinant colonies are white because the insertion disrupts the lacZ gene, preventing blue color formation.

Found an issue with this question?