Annelida is advanced over nematoda in having

Options

A. Closed circulation
B. Metameric segmentation
C. True coelom
D. All the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Phyla**: Annelida and Nematoda are two different phyla within the animal kingdom. Annelids are segmented worms, while nematodes are roundworms.

2. **Closed Circulatory System**: One of the key advancements of Annelida over Nematoda is the presence of a closed circulatory system. In Annelida, blood is contained within vessels, allowing for more efficient transport of nutrients and oxygen compared to the open circulatory system found in Nematoda.

3. **Metamerism**: Annelids exhibit metamerism, which means their bodies are divided into segments. This segmentation allows for greater complexity in body structure and function, which is not present in Nematoda.

4. **True Coelom**: Annelids possess a true coelom, which is a body cavity completely lined by mesoderm. This feature allows for the development of more complex organ systems. In contrast, nematodes have a pseudocoelom, which is not fully lined by mesoderm.

5. **Conclusion**: Based on these characteristics, Annelida is considered more advanced than Nematoda due to the presence of a closed circulatory system, metameric segmentation, and a true coelom.

**Final Answer**: Annelida is advanced over Nematoda in having a closed circulatory system, metameric segmentation, and a true coelom.

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