The Nissl's bodies of cyton represent 

Options

A. Golgi complex of neuron
B. RER, the sites of protein synthesis
C. Nucleus, site of synthesis amino acids
D. SER, the sites of lipids

Answer

To answer the question "The Nissl's bodies of cyton represent," we will analyze the options provided and identify the correct one step by step.

### Step-by-Step Solution:

1. **Understanding Nissl's Bodies**:
- Nissl's bodies are large granular structures found in the cell body (cyton) of neurons. They are primarily composed of rough endoplasmic reticulum (RER) and ribosomes.

2. **Identifying the Function of Nissl's Bodies**:
- The main function of Nissl's bodies is protein synthesis. The rough endoplasmic reticulum (RER) is responsible for synthesizing proteins that are essential for the functioning of the neuron.

3. **Evaluating the Options**:
- **Option A**: Golgi complex of neuron - This is involved in modifying, sorting, and packaging proteins but is not what Nissl's bodies represent.
- **Option B**: RER (Rough Endoplasmic Reticulum) - This is indeed the structure that makes up Nissl's bodies and is the site of protein synthesis.
- **Option C**: Nucleus - While the nucleus is involved in synthesizing RNA and assembling amino acids, it does not represent Nissl's bodies.
- **Option D**: SER (Smooth Endoplasmic Reticulum) - This is involved in lipid synthesis and metabolic processes, not protein synthesis.

4. **Conclusion**:
- Based on the analysis, the correct answer is **Option B: RER (Rough Endoplasmic Reticulum)**, as Nissl's bodies are primarily composed of RER and are the sites of protein synthesis in neurons.

### Final Answer:
The Nissl's bodies of cyton represent **Rough Endoplasmic Reticulum (RER)**.