The replication of DNA is a pre-requisite for a cukaryotic cell to undergo division. During the cell cycle, the DNA replicates in

Options

A. S-phase
B. ` G_(1)`-phase
C. `G_(2)`-phase
D. M-phase

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
- The question asks about the specific phase of the cell cycle during which DNA replication occurs in eukaryotic cells.

2. **Identifying the Phases of the Cell Cycle:**
- The cell cycle consists of several phases: G1 phase (Gap 1), S phase (Synthesis), G2 phase (Gap 2), and M phase (Mitosis).

3. **Analyzing Each Phase:**
- **G1 Phase:** This is the first gap phase where the cell grows and synthesizes proteins and RNA. DNA replication does not occur here.
- **S Phase:** This is the synthesis phase where DNA replication takes place. The genetic material is duplicated in preparation for cell division.
- **G2 Phase:** This is the second gap phase where the cell prepares for mitosis. It focuses on synthesizing proteins necessary for cell division but does not involve DNA replication.
- **M Phase:** This is the mitotic phase where the cell divides into two daughter cells. DNA replication has already occurred prior to this phase.

4. **Conclusion:**
- The correct answer to the question is that DNA replication occurs during the **S phase** of the cell cycle.

**Final Answer:**
- DNA replicates during the **S phase** of the cell cycle.

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