Nissl's granules are absent in

Options

A. Dendrons and dendrites
B. Cyton
C. axon
D. Dendrons and cyton

Answer

To solve the question "Nissl's granules are absent in," we need to analyze the options provided and understand the characteristics of Nissl's granules.

### Step-by-Step Solution:

1. **Understanding Nissl's Granules**:
- Nissl's granules are structures found in neurons, primarily composed of rough endoplasmic reticulum (RER) and ribosomes. They are involved in protein synthesis.

2. **Identifying Locations of Nissl's Granules**:
- Nissl's granules are predominantly found in the cell body of the neuron, also known as the cyton or soma.
- They are also present in dendrites (the branched extensions of the neuron that receive signals).

3. **Analyzing the Options**:
- **Option 1: Dendrons and Dendrites**: Nissl's granules are present in both dendrons and dendrites.
- **Option 2: Cytons**: Nissl's granules are present in cytons (the cell body of the neuron).
- **Option 3: Axons**: Nissl's granules are absent in axons. The axon is the long, slender projection of a neuron that conducts electrical impulses away from the cell body, and it does not contain Nissl's granules.
- **Option 4: Dendrons and Cytons**: Nissl's granules are present in both dendrons and cytons.

4. **Conclusion**:
- Since Nissl's granules are specifically absent in the axon, the correct answer to the question is **Option 3: Axons**.

### Final Answer:
Nissl's granules are absent in **Axons**.