__________ phase marks the end of M-phase.

Options

A. Karyokinesis
B. Prophase
C. Cytokinesis
D. Telophase

Answer

To answer the question "__________ phase marks the end of M-phase," we need to understand the components of the M-phase (mitotic phase) in the cell cycle.

### Step-by-Step Solution:

1. **Understanding M-phase**: The M-phase, or mitotic phase, is the part of the cell cycle where cell division occurs. It consists of two main processes: karyokinesis and cytokinesis.

2. **Karyokinesis**: This is the first part of the M-phase, which involves the division of the nucleus. Karyokinesis itself is divided into four stages: prophase, metaphase, anaphase, and telophase.

3. **Cytokinesis**: After karyokinesis, the next step is cytokinesis. This process involves the division of the cytoplasm, resulting in two separate daughter cells.

4. **End of M-phase**: The M-phase is considered complete when both the nucleus and the cytoplasm have been divided. Therefore, the phase that marks the end of the M-phase is cytokinesis.

5. **Conclusion**: The correct answer to the question is "cytokinesis," as it is the final step that completes the cell division process.

### Final Answer:
**Cytokinesis** marks the end of M-phase.

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