When dividing cells are examined under a light microscope, chromosomes first become visible during-

Options

A. lnterphase
B. The S Phase
C. Prophase
D. `G_(1)`

Answer

To determine when chromosomes first become visible during cell division, we need to analyze the stages of the cell cycle and the characteristics of each phase.

### Step-by-Step Solution:

1. **Understand the Cell Cycle Phases**: The cell cycle consists of several phases: G1 (Gap 1), S (Synthesis), G2 (Gap 2), and M (Mitosis). Mitosis is further divided into prophase, metaphase, anaphase, and telophase.

2. **Identify Interphase**: The first three phases (G1, S, and G2) are collectively known as interphase. During interphase, the DNA is in the form of chromatin, which is not visible under a light microscope.

3. **Recognize the Start of Mitosis**: Mitosis (M phase) is where the actual division of the cell occurs, and it is during this phase that chromosomes become visible.

4. **Focus on Prophase**: Prophase is the first stage of mitosis. During prophase, the chromatin condenses into distinct chromosomes, making them visible under a light microscope.

5. **Conclusion**: Since chromosomes are first visible at the beginning of mitosis, specifically during prophase, the answer to the question is that chromosomes first become visible during prophase.

### Final Answer:
Chromosomes first become visible during **Prophase**.

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