Tube feet of echinoderms help in ……….. and ………. .

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Echinoderms**: Echinoderms are a group of marine animals that exhibit radial symmetry and have a unique water vascular system. This group includes species such as starfish, sea urchins, and sea cucumbers.

2. **Identifying Tube Feet**: Tube feet are small, flexible, and hydraulic structures that extend from the body of echinoderms. They are part of the water vascular system, which is a distinctive feature of this phylum.

3. **Function of Tube Feet**: The tube feet serve two primary functions:
- **Locomotion**: Tube feet help echinoderms move around. They can extend and contract, allowing the animal to crawl or walk along the sea floor.
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