Question

Assertion (A): A piece of DNA inserted into an alien organism generally does not replicate, if not inserted into a chromosome.
Reason (R): Chromosomes have specific sequences called ‘ori’ region, where DNA replication is initiated.

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

‘Ori’ regions are essential starting points for replication in both plasmids and chromosomes.

Answer 1

The Correct Option is A

For DNA to replicate inside a host organism, it must have an origin of replication (ori). If a foreign DNA lacks this sequence, it won’t replicate unless integrated into a chromosome containing an ‘ori’ site. Thus, both the assertion and reason are true and the reason correctly explains the assertion.