Phylum ctenphora

Options

A. Crustacea and arachnida
B. polychaeta and hirudinea
C. tentaculata and nuda
D. calcarea and demospongiae

Answer

### Step-by-Step Solution for Phylum Ctenophora

1. **Definition of Phylum Ctenophora**:
- Ctenophora, commonly known as comb jellies, is a phylum of marine invertebrates characterized by their unique locomotion using cilia.

2. **Classes of Ctenophora**:
- There are two main classes within the phylum Ctenophora:
- **Tentaculata**: This class includes organisms that possess large, visible tentacles. They also have specialized structures known as comb plates, which are used for locomotion.
- **Nuda**: This class includes organisms that do not have tentacles.

3. **Examples of Ctenophora**:
- Common examples include species like *Beroe*, which is a type of comb jelly.

4. **Distinction from Other Phyla**:
- It's important to distinguish Ctenophora from other phyla:
- Classes like Crustacea and Arachnida belong to Phylum Arthropoda.
- Classes such as Polychaeta and Hirudinia belong to Phylum Annelida.
- Calcarea and Demospongia are classes under Phylum Porifera.

5. **Conclusion**:
- The correct classification for the classes of Phylum Ctenophora is Tentaculata and Nuda.