A cell is bound to divide, if it has entered :-

Options

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

Answer

To determine when a cell is bound to divide, we need to analyze the different phases of the cell cycle. Here’s a step-by-step breakdown of the reasoning:

### Step 1: Understanding the Cell Cycle Phases
The cell cycle consists of several phases: G1 (Gap 1), S (Synthesis), G2 (Gap 2), and M (Mitosis). Each phase has specific functions and prepares the cell for division.

### Step 2: Analyzing Each Phase
1. **G1 Phase**: This is the first phase after cell division. During G1, the cell grows and synthesizes proteins necessary for DNA replication. However, the cell is not yet committed to division.

2. **S Phase**: This phase is crucial as it is when DNA replication occurs. The cell duplicates its genetic material, preparing for the eventual division. If a cell has entered the S phase, it is committed to dividing because it needs to separate the replicated DNA during mitosis.

3. **G2 Phase**: In this phase, the cell continues to grow and prepares for mitosis by synthesizing proteins and organelles. While the cell is preparing for division, it is not yet in the process of dividing.

4. **Prophase**: This is the first stage of mitosis, where the chromatin condenses into visible chromosomes, and the nuclear envelope begins to break down. However, the cell must first complete the S phase to reach this point.

### Step 3: Conclusion
Based on the analysis, the cell is bound to divide if it has entered the **S phase**. This is the phase where DNA replication occurs, making it essential for the cell to prepare for division.

### Final Answer:
The correct answer is the **S phase**.

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