Secondary lysosomes are also called

Options

A. Autophagic vacuoles
B. Lipofuscin granules
C. Residual body
D. Heterophagosomes

Explanation

**Step-by-Step Solution:**

1. **Understanding Lysosomes**:
- Lysosomes are membrane-bound organelles found in the cytoplasm of eukaryotic cells. They contain hydrolytic enzymes that are crucial for breaking down waste materials and cellular debris.

2. **Primary vs. Secondary Lysosomes**:
- Primary lysosomes are formed from the Golgi apparatus and contain inactive enzymes. When they fuse with a vacuole containing material to be digested, they become secondary lysosomes.

3. **Definition of Secondary Lysosomes**:
- Secondary lysosomes are involved in the digestion process. They are formed when primary lysosomes merge with phagosomes (vacuoles containing engulfed material).

4. **Alternative Names for Secondary Lysosomes**:
- Secondary lysosomes are also referred to as heterophagosomes or phagolysosomes. They can also be called autophagic vacuoles or residual bodies depending on the context of their function.

5. **Identifying the Correct Answer**:
- Among the options provided, the term "heterophagosomes" is specifically used to refer to secondary lysosomes. Therefore, the correct answer to the question is that secondary lysosomes are also called heterophagosomes.

**Final Answer**: Secondary lysosomes are also called heterophagosomes.

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