Ques. 1AIPMT 2004
In the somatic cell cycle
- in G1 phase DNA content is double the amount of DNA present in the original cell
- DNA replication takes place in S phase
- a short interphase is followed by a long mitotic phase
- G2 phase follows mitotic phase
Answer
(2) DNA replication takes place in S phase
Solution
As per NCERT, S (synthesis) phase is the period during which DNA synthesis or replication takes place; the amount of DNA per cell doubles (2C → 4C).
In G1 the DNA content is not doubled; interphase is long (> 95% of the cycle) and M phase is short; G1 (not G2) follows M phase.
Answer: (2)