In Metaphase I, from each centromere of a chromosome, how many chromosomal fibres (Tractile fibres) arise towards poles ?

Options

A. 2
B. 1
C. `4-20`
D. 4

Answer

To solve the question regarding how many chromosomal fibers (tractile fibers) arise from each centromere of a chromosome towards the poles during Metaphase I, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Chromosome Structure**:
- A chromosome consists of two sister chromatids connected at a region called the centromere.

2. **Identifying the Role of Spindle Fibers**:
- During cell division, spindle fibers (also known as tractile fibers) are crucial for the movement and alignment of chromosomes. They extend from the poles of the cell to the kinetochores located at the centromeres of the chromosomes.

3. **Analyzing Metaphase I**:
- In Metaphase I of meiosis, homologous chromosomes align at the equatorial plate. Each chromosome is attached to spindle fibers that help in their alignment and eventual separation.

4. **Counting the Fibers**:
- From each centromere of a chromosome, there are two spindle fibers extending towards the poles: one fiber extends towards one pole and the other fiber extends towards the opposite pole.

5. **Conclusion**:
- Therefore, from each centromere of a chromosome, **2 chromosomal fibers (tractile fibers)** arise towards the poles.

### Final Answer:
**2**

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