Condensation of chromosome with visible centromere occurs during

Options

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

Answer

To determine during which phase the condensation of chromosomes with visible centromeres occurs, we can analyze the different phases of the cell cycle:

1. **Understanding the Cell Cycle Phases**:
- The cell cycle consists of several phases: G1 phase, S phase, G2 phase, and M phase.
- G1, S, and G2 phases are collectively known as interphase, which is a period of growth and preparation for cell division.

2. **Interphase (G1, S, G2)**:
- During interphase, the cell is metabolically active but not dividing.
- In these phases, chromosomes are not condensed; they exist in a less compact form known as chromatin. Therefore, we cannot see distinct chromosomes or centromeres during these phases.

3. **M Phase (Mitotic Phase)**:
- The M phase is where actual cell division occurs, and it includes stages such as prophase, metaphase, anaphase, and telophase.
- During prophase, the chromosomes begin to condense and become visible under a microscope. This is when the centromeres also become visible, as the chromosomes are now distinct entities.

4. **Conclusion**:
- The condensation of chromosomes with visible centromeres occurs during the M phase, specifically starting in prophase.

Thus, the correct answer is **M phase** (option number 4).

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