Question

Assertion (A): Every chromosome during metaphase has two chromatids.

Reason (R): Synthesis of DNA takes places in the S-phase of interphase.

पर्याय

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

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

• A is true but R is false.

• A is false but R is true.

Answer 1

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

Explanation:

The assertion is true because each chromosome visible at metaphase is composed of two identical sister chromatids held together at the centromere. The reason is also true because DNA replication happens exclusively during the S-phase of interphase. However, this is not the correct explanation because it describes DNA replication rather than the structural formation of the double-chromatid state observed during metaphase alignment.