Characteristic feature of coelenterata is

Options

A. All are marine
B. Presence of tentacles around mouth
C. Polyp
D. Gastrovascular cavity

Answer

To determine the characteristic feature of Coelenterata (also known as Cnidaria), we will analyze the options provided and identify the correct one step by step.

### Step-by-Step Solution:

1. **Understanding Coelenterata**: Coelenterata is a phylum that includes organisms such as jellyfish, corals, and sea anemones. They are known for their unique body structure and functions.

2. **Evaluating the Options**:
- **Option A: All are marine**: While many Coelenterates are marine, this is not a defining characteristic, as some can be found in freshwater. Therefore, this option is incorrect.
- **Option B: Presence of tentacles around the mouth**: While many Coelenterates do have tentacles, this feature is not exclusive to them and can be found in other organisms as well. Thus, this option is also incorrect.
- **Option C: Polyp**: Coelenterates can exist in polyp and medusa forms, but the presence of polyp alone is not a defining characteristic of the phylum. Hence, this option is incorrect.
- **Option D: Gastrovascular cavity**: This is a central body cavity found in Coelenterates, which is responsible for digestion and circulation. It is a unique feature that distinguishes them from other phyla. Therefore, this option is correct.

3. **Conclusion**: The characteristic feature of Coelenterata is the presence of a gastrovascular cavity.

### Final Answer:
The characteristic feature of Coelenterata is the gastrovascular cavity.

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