Pearl is formed when a foreign substance gets trapped between A of B

Options

A. A- Shell and mantle B - Pila
B. A- Nacreous and prismatic layer B-Pinctada
C. A - Shell and mantle B Pinctada
D. A- Nacreous and prismatic layer B- Ostrea

Answer

To answer the question "Pearl is formed when a foreign substance gets trapped between A and B," we need to identify what A and B refer to in the context of pearl formation.

### Step-by-Step Solution:

1. **Understanding Pearl Formation**:
- Pearls are formed by certain mollusks as a defense mechanism against irritants such as a grain of sand or a foreign substance that enters their shell.

2. **Identifying A and B**:
- In the context of the question, A refers to the "cell" and "mantle," while B refers to the organism that produces the pearl, which is typically a type of mollusk.

3. **The Role of the Mantle**:
- The mantle is a significant part of the mollusk's anatomy that secretes layers of nacre (mother of pearl) around the irritant. This secretion forms the layers of the pearl.

4. **Selecting the Correct Option**:
- From the options provided, we need to find the correct pairing of A and B. The correct answer is:
- A: Cell and Mantle
- B: Pinctada (a genus of pearl oysters)

5. **Conclusion**:
- Therefore, the correct answer is that a pearl is formed when a foreign substance gets trapped between the cell and mantle of the Pinctada.

### Final Answer:
Pearl is formed when a foreign substance gets trapped between the cell and mantle of Pinctada.

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