Which chromosome does not provide attachment site for spindle fibers :–

Options

A. Acrocentric
B. Metacentric
C. Submeta centric
D. Acentric

Answer

**Step-by-Step Solution:**

1. **Understanding Spindle Fiber Attachment**: Spindle fibers are crucial for chromosome movement during cell division. They attach to chromosomes at a specific region known as the centromere.

2. **Identifying Chromosome Types**: Chromosomes can be categorized based on the position of their centromeres:
- **Metacentric**: Centromere is located at the center, resulting in two equal arms.
- **Submetacentric**: Centromere is slightly off-center, leading to unequal arms (p and q).
- **Acrocentric**: Centromere is closer to one end, resulting in one very short arm and one very long arm.
- **Telocentric**: Centromere is at the terminal end, resulting in only one arm.

3. **Finding the Exception**: The key to answering the question lies in identifying which type of chromosome lacks a centromere. The only type that does not have a centromere is the **acentric chromosome**.

4. **Conclusion**: Since the acentric chromosome does not have a centromere, it cannot provide an attachment site for spindle fibers. Therefore, the answer to the question is **acentric chromosome**.

**Final Answer**: The chromosome that does not provide an attachment site for spindle fibers is the **acentric chromosome**.

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