Spindle fibres attach on to

Options

A. kinetochore of the chromosome
B. centromere of the chromosome
C. kinetosome of the chromosome
D. telomere of the chromosome

Answer

**Step-by-Step Solution:**

1. **Understanding Spindle Fibers**: Spindle fibers are structures that form during cell division (mitosis and meiosis) to help separate chromosomes. They are composed of microtubules.

2. **Identifying Attachment Points**: Spindle fibers attach to specific regions of the chromosomes. The main points of attachment are:
- **Kinetochore**: A protein structure on the chromosome where spindle fibers attach.
- **Centromere**: The region of the chromosome where the two sister chromatids are joined, and where the kinetochore is located.
- **Kinetosome**: This term is less commonly used, but it refers to the basal body of a cilium or flagellum, not directly related to spindle fibers.
- **Telomere**: The ends of the chromosomes, which do not serve as attachment points for spindle fibers.

3. **Correct Answer**: The spindle fibers primarily attach to the **kinetochore** of the chromosome, which is located at the centromere.

4. **Metaphase Stage**: During metaphase, chromosomes align at the cell's equatorial plane, and spindle fibers are fully attached to the kinetochores of the chromosomes, ensuring proper separation during the next phase of cell division.

**Final Answer**: Spindle fibers attach to the **kinetochore** of the chromosome.

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