What is metamerism?

Options

A. Both sponge
B. Jelly fish
C. Planarian
D. Polycheete

Answer

**Step-by-Step Solution:**

1. **Definition of Metamerism**: Metamerism refers to the segmentation of an organism's body into repeated sections, known as metameres or somites. This is a characteristic feature of certain animal phyla.

2. **Examples of Metamerism**: Metamerism is most commonly observed in annelids (like earthworms), arthropods (like insects), and some chordates (like vertebrates). Each segment can contain similar structures such as muscles, nerves, and blood vessels.

3. **Significance of Metamerism**: Metamerism allows for greater flexibility and mobility in organisms. It also enables more complex body plans and the specialization of segments for different functions.

4. **Comparison with Non-Metameric Organisms**: In contrast to metameric organisms, non-metameric organisms (like sponges and jellyfish) do not have a segmented body structure. Instead, their body plans are more uniform and less complex.

5. **Conclusion**: In summary, metamerism is a key evolutionary adaptation that contributes to the diversity and complexity of body structures in various animal groups.

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