Colchicine is a chemical that stop chromatids from separating during mitosis. If a cell is treated with colchicine , at which stage of mitosis will this cell reach but not complete ?

Options

A. Anaphase
B. Metaphase
C. Telophase
D. Cytokinesis

Answer

To solve the question regarding the effect of colchicine on mitosis, we need to understand the stages of mitosis and the role of colchicine in this process.

### Step-by-Step Solution:

1. **Understanding Mitosis**: Mitosis is the process of cell division that occurs in several stages: prophase, metaphase, anaphase, and telophase. Each stage has specific events that lead to the successful division of a cell.

2. **Role of Colchicine**: Colchicine is a chemical that disrupts the formation of the spindle apparatus, which is crucial for the separation of chromatids during mitosis. By inhibiting spindle formation, colchicine prevents the proper functioning of microtubules.

3. **Identifying the Stages**:
- **Prophase**: Chromosomes condense, and the nuclear membrane begins to break down.
- **Metaphase**: Chromosomes align at the equatorial plane of the cell, and the spindle apparatus is fully formed.
- **Anaphase**: The spindle fibers pull the sister chromatids apart toward opposite poles of the cell.
- **Telophase**: The nuclear membrane re-forms around each set of separated chromosomes.

4. **Effect of Colchicine**: Since colchicine inhibits spindle formation, the cell will not be able to proceed past the metaphase stage. The chromosomes will align at the equator, but without the spindle fibers, they cannot be pulled apart to enter anaphase.

5. **Conclusion**: Therefore, if a cell is treated with colchicine, it will reach the **metaphase** stage of mitosis but will not be able to complete the process, as it cannot progress to anaphase.

### Final Answer:
The cell will reach the **metaphase** stage of mitosis but will not complete it.