Heterophagosomes are

Options

A. Primary lysosomes
B. Secondary lysosomes
C. Autophagic vacuole
D. Tertiary lysosomes

Answer

**Step-by-Step Solution:**

1. **Understanding Heterophagosomes**: Heterophagosomes are structures within cells that are involved in the degradation of foreign materials. They are specifically classified as secondary lysosomes.

2. **Role of Lysosomes**: Lysosomes are organelles that contain digestive enzymes. Their primary function is to break down waste materials and cellular debris, including foreign substances that enter the cell.

3. **Formation of Phagosomes**: When a foreign material enters the cell, it is engulfed by the cell membrane through a process called phagocytosis. This process results in the formation of a phagosome, which is a vesicle that contains the ingested material.

4. **Fusion of Phagosome and Lysosome**: The phagosome then fuses with a primary lysosome. This fusion creates a new structure known as a secondary lysosome or heterophagosome. This is where the degradation of the foreign material occurs.

5. **Conclusion**: Therefore, heterophagosomes can be defined as secondary lysosomes formed when a phagosome fuses with a lysosome. They play a crucial role in the cellular defense mechanism against foreign invaders.

**Final Answer**: Heterophagosomes are secondary lysosomes formed by the fusion of phagosomes with lysosomes, involved in the degradation of foreign materials.

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