In mollusca which type of cleavage is found?

Options

A. Spiral
B. Radial
C. Bilateral
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Cleavage**: Cleavage refers to the series of cell divisions that occur after fertilization. It is a crucial process in early embryonic development.

2. **Types of Cleavage**: There are different types of cleavage patterns observed in various organisms, including spiral, radial, and bilateral cleavage.

3. **Identifying Cleavage in Mollusca**: In the case of mollusks, the type of cleavage that is primarily observed is spiral cleavage.

4. **Description of Spiral Cleavage**: Spiral cleavage is characterized by the arrangement of cells in a spiral pattern as they divide. This means that the cells do not divide symmetrically but rather at an angle to the previous cell division.

5. **Example of Spiral Cleavage**: An example of an organism that exhibits spiral cleavage is the snail, which is a member of the mollusks. This type of cleavage is significant as it contributes to the developmental process, including the ability of torsion in snails.

6. **Conclusion**: Therefore, the type of cleavage found in Mollusca is spiral cleavage.

**Final Answer**: Spiral cleavage is found in Mollusca.

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