Nissl granules in cyton of nerves are rich in

Options

A. RER
B. Golgi bodies
C. Mitochondria
D. SER

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks about the composition of Nissl granules found in the cyton (cell body) of nerve cells.

2. **Identifying Nissl Granules**: Nissl granules are large granular bodies found in neurons. They are primarily associated with the rough endoplasmic reticulum (RER).

3. **Function of Nissl Granules**: The main function of Nissl granules is to synthesize proteins. This is because they are rich in rough endoplasmic reticulum, which is involved in the production of proteins.

4. **Analyzing the Options**:
- **Rough Endoplasmic Reticulum**: This is the correct answer as it is responsible for protein synthesis and is abundant in Nissl granules.
- **Golgi Bodies**: These are involved in the packaging of proteins, not their synthesis, making this option incorrect.
- **Mitochondria**: Known as the powerhouse of the cell, they are primarily involved in energy production, not in protein synthesis, thus this option is incorrect.
- **Smooth Endoplasmic Reticulum**: This structure is involved in lipid synthesis, which does not relate to the function of Nissl granules, making this option incorrect as well.

5. **Conclusion**: Based on the analysis, the correct answer is that Nissl granules in the cyton of nerves are rich in **rough endoplasmic reticulum**.

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