Whose secretion forms the pearl?

Options

A. Prismatic layer
B. Columnar epithelial cells of mantle
C. Ciliated epithelial cells of mantle
D. Connective tissue of mantle

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the origin of the secretion that forms pearls.

2. **Identifying the Organism**: Pearls are formed by mollusks, specifically by oysters. Mollusks belong to the phylum Mollusca, which is known for its diverse species.

3. **Pearl Formation Process**: Pearls are formed as a response to irritation. When a foreign body, such as a grain of sand or a parasite, enters the mantle tissue of the oyster, it causes irritation.

4. **Role of Mantle**: The mantle is a significant part of the mollusk's anatomy. It is responsible for secreting substances that contribute to the formation of pearls.

5. **Secretion Components**: The secretion that forms pearls primarily consists of calcium carbonate and a protein called conchiolin.

6. **Epithelial Cells Involved**: The specific cells responsible for the secretion of these materials are the columnar epithelial cells of the mantle.

7. **Final Conclusion**: Therefore, the secretion that forms pearls comes from the columnar epithelial cells of the mantle in mollusks.

**Answer**: The secretion that forms the pearl comes from the columnar epithelial cells of the mantle.

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