The members of which group do not exhibit metamerism

Options

A. Pisces
B. Aves
C. Arthropoda
D. Mollusca

Answer

**Step-by-Step Solution:**

1. **Understanding Metamerism**: Metamerism refers to the segmentation of the body into repeated units called metameres. This is a characteristic feature of certain animal groups.

2. **Identifying Groups with Metamerism**:
- **Pisces (Fishes)**: Fishes exhibit metamerism as their bodies are segmented into distinct parts.
- **Aves (Birds)**: Birds also show metameric segmentation, with their bodies divided into segments.
- **Arthropoda (Insects, Arachnids, Crustaceans)**: This group is well-known for its segmented body structure.

3. **Identifying Groups without Metamerism**:
- **Mollusca**: This group includes organisms like snails, clams, and squids. Mollusks do not exhibit metamerism. Instead, their bodies are typically divided into a muscular foot, visceral mass, and mantle, but they lack the segmented body structure seen in the other groups mentioned.

4. **Conclusion**: Based on the analysis, the group that does not exhibit metamerism is **Mollusca**.

5. **Final Answer**: The members of the group **Mollusca** do not exhibit metamerism.

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