Swellings present over the chromosomes are

Options

A. Centromeres
B. Centrosome
C. Puffs
D. Chromomeres

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the swellings present over the chromosomes. We need to identify the correct term that describes these structures.

2. **Analyzing the Options**: The options provided are:
- Centromeres
- Centrosome
- Puffs
- Chromomeres

3. **Defining Each Option**:
- **Centromeres**: This is the region of a chromosome where the two sister chromatids are joined together. It plays a crucial role during cell division but does not refer to swellings.
- **Centrosome**: This is an organelle that serves as the main organizing center for microtubules and is involved in the formation of the spindle fibers during cell division. It is not related to the structure of chromosomes.
- **Puffs**: These are localized swellings on the chromosomes that occur during certain stages of gene activity, but they are not the general term for the bead-like structures formed by DNA coiling.
- **Chromomeres**: These are the bead-like structures formed on chromosomes due to the local coiling of the DNA. They represent regions of compacted chromatin.

4. **Identifying the Correct Answer**: Based on the definitions, the swellings present over the chromosomes are best described as **chromomeres**.

5. **Final Answer**: The correct answer is **chromomeres** (Option 4).

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