Colchicine prevents the mitosis of cells at which of the following stage?

Options

A. Anaphase
B. Metaphase
C. Prophase
D. Interphase

Answer

**Step-by-Step Solution:**

1. **Understanding Colchicine:** Colchicine is known as an anti-mitotic drug. This means it interferes with the process of mitosis, which is the division of a cell into two daughter cells.

2. **Identifying the Cell Cycle Phases:** The cell cycle consists of several phases, and mitosis is a crucial part of this cycle. Mitosis can be divided into several stages: prophase, metaphase, anaphase, and telophase.

3. **Focusing on Karyokinesis:** Karyokinesis refers specifically to the division of the nucleus during mitosis. It is a part of the M phase of the cell cycle.

4. **Analyzing the Stages of Mitosis:**
- **Prophase:** The nuclear envelope breaks down, and the chromatin condenses into visible chromosomes.
- **Metaphase:** Chromosomes align at the cell's equatorial plane, and the mitotic spindle forms, connecting to the centromeres of the chromosomes.
- **Anaphase:** Sister chromatids are pulled apart to opposite poles of the cell.
- **Telophase:** The chromosomes de-condense, and the nuclear envelope reforms around each set of chromosomes.

5. **Effect of Colchicine:** Colchicine specifically disrupts the formation of the mitotic spindle by preventing the arrangement of microtubules. This action halts the process of mitosis at the metaphase stage, as the chromosomes cannot align properly without the spindle apparatus.

6. **Conclusion:** Therefore, colchicine prevents mitosis at the **metaphase stage**.

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