Question

In which stage of the cell cycle does DNA replication occur?

• A. G1 phase
• B. S phase
• C. G2 phase
• D. M phase

Hint:

The S phase of the cell cycle is where DNA replication takes place, ensuring that each daughter cell receives a complete set of chromosomes.

Answer 1

The Correct Option is B

The cell cycle consists of several stages that prepare a cell for division. The stages are G1, S, G2, and M phases. - Option (1) is incorrect: The G1 phase is the first growth phase of the cell cycle, where the cell grows and performs its normal functions but does not replicate DNA.
- Option (2) is correct: The S phase (Synthesis phase) is when DNA replication occurs. The cell copies its entire genome in preparation for cell division.
- Option (3) is incorrect: The G2 phase is the second growth phase, where the cell continues to grow and prepares for mitosis, but no DNA replication takes place.
- Option (4) is incorrect: The M phase (Mitosis phase) is when the cell actually divides, but DNA replication has already occurred during the S phase.
Thus, DNA replication occurs during the S phase of the cell cycle.