Metamerism is characteristic of phylum

Options

A. Platylielminthes
B. annelida
C. Porifera
D. Ctenophora

Answer

To determine which phylum exhibits metamerism, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Metamerism**: Metamerism refers to the segmentation of the body into repeated units called metameres. Each segment can contain organs and structures that are repeated throughout the body.

2. **Evaluate the Options**:
- **Platyhelminthes**: This phylum includes flatworms, which do not exhibit metamerism. They have a flat body structure and are not segmented.
- **Annelida**: This phylum includes segmented worms like earthworms and leeches. Annelids are characterized by their segmented bodies, which is a clear example of metamerism.
- **Porifera**: This phylum includes sponges, which are not segmented and do not exhibit metamerism.
- **Ctenophora**: This phylum includes comb jellies, which also do not show metamerism.

3. **Identify the Correct Phylum**: Based on the evaluation, Annelida is the only phylum among the options that exhibits metamerism.

4. **Conclusion**: The correct answer to the question is **Annelida**.

### Final Answer:
Metamerism is characteristic of phylum **Annelida**.

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