Chromatid-type breaks occur during the cell cycle in the

Options

A. S phase
B. `G_1` phase
C. `G_2` phase
D. mitosis

Answer

**Step-by-Step Solution:**

1. **Understanding Chromatid-Type Breaks**: Chromatid-type breaks refer to the breaks that occur in the chromatids during the cell cycle. These breaks can affect the genetic material during cell division.

2. **Identifying the Cell Cycle Phases**: The cell cycle consists of several phases including:
- G1 phase (Gap 1)
- S phase (Synthesis)
- G2 phase (Gap 2)
- M phase (Mitosis), which includes sub-phases like prophase, metaphase, anaphase, and telophase.

3. **Focusing on Mitosis**: Among these phases, mitosis is the primary phase where chromatid-type breaks are relevant. Mitosis is responsible for the division of the cell's nucleus and the distribution of genetic material to daughter cells.

4. **Identifying the Specific Stage**: Within mitosis, the anaphase stage is critical for chromatid-type breaks. During anaphase, the sister chromatids are pulled apart towards opposite poles of the cell.

5. **Mechanism of Chromatid-Type Breaks**: The breaks occur at the centromere, which is the region where the two sister chromatids are joined. The spindle fibers attach to the centromeres and facilitate the separation of the chromatids.

6. **Conclusion**: Therefore, chromatid-type breaks occur during the anaphase of mitosis, specifically at the centromere where the sister chromatids are separated by spindle fibers.

**Final Answer**: Chromatid-type breaks occur during the cell cycle in the anaphase stage of mitosis.

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