Spindle fibres are attached to kinetochores of chromosomes in

Options

A. a. Metaphase
B. b. Anaphase
C. c.Telophase
D. d. 1 and 2

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks in which phase of cell division spindle fibers are attached to the kinetochores of chromosomes.

2. **Identify Key Terms**:
- **Spindle Fibers**: Protein structures that help in the separation of chromosomes during cell division.
- **Kinetochores**: Disc-like structures located at the centromere of chromosomes where spindle fibers attach.

3. **Analyze the Options**: The options provided are:
- Metaphase
- Anaphase
- Telophase
- 1 and 2 (which refers to Metaphase and Anaphase)

4. **Review Each Phase**:
- **Metaphase**: During this phase, chromosomes align at the cell's equatorial plane, and spindle fibers attach to the kinetochores of the chromosomes. This is the key phase where the attachment occurs.
- **Anaphase**: In this phase, the spindle fibers pull the sister chromatids apart towards opposite poles of the cell. While spindle fibers are present, they are not attached to kinetochores in the same way as in metaphase.
- **Telophase**: This is the final phase where the spindle fibers begin to disappear, and the cell starts to divide. There is no attachment to kinetochores at this stage.

5. **Conclusion**: The only phase where spindle fibers are actively attached to kinetochores is during **Metaphase**. Therefore, the correct answer is **Metaphase**.

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