Question

In which phase of the cell cycle, synthesis of DNA is completed

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

Answer 1

The correct option is B

S phase

The correct option is B.

Explanation of correct option:

1. A cell cycle is a set of events that occur in a cell when it divides and grows.
2. It comprises four phases - M phase, G₁ phase, S phase, and G₂ phase.
3. Interphase includes G₁, S, and G₂ phases.
4. Interphase refers to the time between two successive cell divisions.
5. Interphase accounts for 95% of the cell cycle's duration.

S phase

1. It occurs after the G₁ phase.
2. This phase is also known as the synthetic phase.
3. Synthesis of DNA occurs in this stage.

Explanation of incorrect options:

Option A: In the M phase cell divides by undergoing 4 stages- Prophase, Metaphase, Anaphase, and telophase. Nuclear division occurs in this phase.

Option C: It is the first gap phase. In this phase, the cell metabolizes nutrients and grows.

Option D: Cell growth occurs in this phase.

Final answer: Synthesis of DNA is completed in the S phase.