The centrosome duplicates during the

Options

A. S - phase of cell cycle
B. G - phase of cell cycle
C. `G_(2)` - phase of cell cycle
D. Prophase of cell cycle

Answer

**Step-by-Step Solution:**

1. **Understanding Centrosomes**: Centrosomes are structures in the cell that consist of two centrioles positioned perpendicularly to each other, surrounded by pericentriolar material. They play a crucial role in cell division by organizing microtubules.

2. **Cell Cycle Overview**: The cell cycle is a series of events that cells go through as they grow and divide. It consists of two main phases: Interphase and M-phase. Interphase is the longer phase, making up about 95% of the cycle, while M-phase (mitotic phase) is shorter, accounting for about 5%.

3. **Phases of Interphase**: Interphase is divided into three sub-phases:
- **G1 Phase (Gap 1)**: The cell grows and carries out normal functions.
- **S Phase (Synthesis)**: This is the phase where DNA replication occurs, and importantly, centrosomes also duplicate during this phase.
- **G2 Phase (Gap 2)**: The cell continues to grow and prepares for mitosis.

4. **M-phase Breakdown**: The M-phase consists of two parts:
- **Karyokinesis**: The division of the nucleus.
- **Cytokinesis**: The division of the cytoplasm.

5. **Conclusion**: The centrosome duplicates specifically during the S phase of the cell cycle, which is the phase dedicated to DNA and centrosome synthesis.

**Final Answer**: The centrosome duplicates during the S phase of the cell cycle.

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