What are Nissl's granules ? Give their functions.

Explanation

### Step-by-Step Text Solution:

1. **Definition of Nissl's Granules**:
Nissl's granules are structures found in the cytoplasm of neurons, specifically in the cell body (cyton) of the neuron. They are composed of rough endoplasmic reticulum (RER) and free ribosomes.

2. **Composition**:
Nissl's granules are primarily made up of ribosomes, which are the sites of protein synthesis. The presence of rough endoplasmic reticulum contributes to the granules' basophilic nature, meaning they have an affinity for basic dyes due to the high RNA content.

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