In which stage of cell cycle, DNA replication occurs?
- G1-phase
- S-phase
- G2-phase
- M-phase
Answer
(2) S-phase
Solution
As per NCERT, interphase is divided into G1 phase, S phase (synthesis) and G2 phase.
⇒ S or synthesis phase marks the period during which DNA synthesis or replication takes place; the amount of DNA per cell doubles (2C → 4C), but the chromosome number does not change.
∴ DNA replication occurs in the S-phase.
Answer: (2)