Nissl's bodies found in neurons are :

Options

A. Made of DNA
B. Masses of ribosome and RER
C. Help in formation of neurofibrils
D. Masses of mitochondria

Answer

**Step-by-Step Solution:**

1. **Understanding Nissl Bodies**: Nissl bodies, also known as Nissl substance, are large granular bodies found within neurons. They are essential components of the neuron.

2. **Composition of Nissl Bodies**: Nissl bodies are primarily composed of ribosomes and rough endoplasmic reticulum (RER). These organelles are crucial for the synthesis of proteins.

3. **Function of Nissl Bodies**: The main function of Nissl bodies is to synthesize and release proteins that are vital for neuronal growth and the regeneration of axons. This makes them important for the metabolic activities of neurons.

4. **Analyzing the Options**:
- Option 1: Made of DNA - This is incorrect as Nissl bodies do not contain DNA.
- Option 2: Masses of ribosomes and rough endoplasmic reticulum - This is correct as it accurately describes the composition of Nissl bodies.
- Option 3: Helpful in the formation of neurofibrils - This is not the primary function of Nissl bodies.
- Option 4: Clusters of mitochondria - This is incorrect as Nissl bodies do not consist of mitochondria.

5. **Conclusion**: The correct answer is that Nissl bodies are masses of ribosomes and rough endoplasmic reticulum.

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