Which of the following is an exclusively echinoderm character ?

Options

A. Tube feet
B. Coelom divided
C. Radial symmetry
D. Mesodermal endoskeleton

Answer

To determine which of the following is an exclusively echinoderm character, we will analyze the characteristics associated with echinoderms and compare them with the options provided.

### Step-by-Step Solution:

1. **Understanding Echinoderms**: Echinoderms are marine animals that include starfish, sea urchins, and sea cucumbers. They are characterized by their unique features.

2. **Identifying Key Features**:
- **Spiny Skin**: Echinoderms have a hard, spiny skin.
- **Water Vascular System**: They possess a water vascular system that aids in locomotion, feeding, and respiration.
- **Tube Feet**: These are extensions of the water vascular system and are used for movement, capturing food, and respiration.
- **Radial Symmetry**: Echinoderms exhibit radial symmetry, especially in their adult forms.

3. **Analyzing the Options**:
- **Option 1: Tube Feet**: These are indeed a characteristic feature of echinoderms and are not found in other groups.
- **Option 2: Coelom Divided**: This feature is not exclusive to echinoderms, as many invertebrates also exhibit a divided coelom.
- **Option 3: Radial Symmetry**: While echinoderms have radial symmetry, this trait is also present in other organisms, such as cnidarians.
- **Option 4: Mesodermal Endoskeleton**: This is a feature of echinoderms but can also be found in some other invertebrates.

4. **Conclusion**: Among the options provided, tube feet are the only feature that is exclusively associated with echinoderms. Therefore, the correct answer is **Option 1: Tube Feet**.