MarksRiser
MarksRiser
Zoology-Recombinant DNA

NEET Zoology Recombinant DNA Assertion Reason Question

Type: Assertion Reason-assertion-Hard-Class 12

Assertion (A): Insertional inactivation results in the production of blue colonies when a chromogenic substrate is present.

Reason (R): A recombinant DNA, when inserted within the coding sequence of β-galactosidase, inactivates the gene for enzyme synthesis.

A

Both (A) and (R) are true and (R) is the correct explanation of (A).

B

Both (A) and (R) are true but (R) is not the correct explanation of (A).

C

(A) is true but (R) is false.

D

(A) is false but (R) is true.

Correct Answer

Option D

Detailed Explanation

The NCERT context states that insertion of recombinant DNA inactivates the β-galactosidase gene, resulting in white colonies, not blue. Thus, (A) is false and (R) is true.

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