Question

Assertion (A): A piece of DNA inserted into an alien organism generally does not replicate, if not inserted into a chromosome.
Reason (R): \textit{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 \textit{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:

DNA without an ori sequence or chromosomal integration cannot replicate in host cells.

Answer 1

The Correct Option is A

For a DNA segment to replicate inside a host, it must contain an origin of replication (ori). If it doesn’t and isn’t inserted into a host chromosome (which does have an ori), it won't be replicated. So both statements are true and the Reason correctly explains the Assertion.