Lipofuscin granules present in nerve cells are actually

Options

A. Primary lysosomes
B. Digestive vacuoles
C. Residual bodies
D. Newly digested lipids.

Answer

### Step-by-Step Solution:

1. **Understanding Lipofuscin Granules**:
- Lipofuscin granules are yellow-brown pigment granules that accumulate in various cells, particularly in nerve cells. They are often referred to as "aging" or "wear and tear" pigments.

2. **Composition of Lipofuscin**:
- These granules contain lipid residues that result from the lysosomal digestion of cellular components. Over time, as cells age, these residues accumulate because they are not completely digested.

3. **Identifying the Options**:
- The question provides four options:
- A) Primary lysosomes
- B) Digestive vessels
- C) Residual bodies
- D) Newly digested lipids

4. **Analyzing the Options**:
- **Primary lysosomes**: These are organelles that contain enzymes for digestion but are not the same as lipofuscin.
- **Digestive vessels**: This term is too vague and does not specifically refer to lipofuscin.
- **Residual bodies**: These are indeed vesicles that contain indigestible material that remains after lysosomal digestion, which aligns with the nature of lipofuscin.
- **Newly digested lipids**: This option does not fit because lipofuscin is not newly digested material but rather the remnants of material that could not be digested.

5. **Conclusion**:
- Based on the analysis, lipofuscin granules present in nerve cells are best classified as **residual bodies**.

### Final Answer:
Lipofuscin granules present in nerve cells are actually **residual bodies**.

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