Which of the following is a non-locomotor movement ?

Options

A. Hydra following its prey
B. A person bending anteriorly
C. Deer running on grassland
D. Snail crawling on sand

Answer

To determine which of the following is a non-locomotor movement, we need to first understand the definitions of locomotor and non-locomotor movements.

### Step-by-Step Solution:

1. **Define Locomotion**:
- Locomotion refers to the ability of an organism to move from one place to another. This can involve various forms of movement, such as walking, running, swimming, or crawling.

2. **Identify Non-Locomotor Movement**:
- Non-locomotor movements are those movements that do not involve a change of position or location. Instead, they involve movements that occur in place, such as bending, twisting, or swaying.

3. **Analyze the Options**:
- **Option A: Hydra following its prey**: This is a locomotor movement because the Hydra is moving from one location to another in pursuit of its prey.
- **Option B: Person bending anteriorly**: This is a non-locomotor movement because the person is bending in place and not changing their location.
- **Option C: Deer running on grassland**: This is a locomotor movement as the deer is moving across the grassland.
- **Option D: Snail crawling on the sand**: This is also a locomotor movement since the snail is moving from one spot to another.

4. **Conclusion**:
- After analyzing all the options, the correct answer is **Option B: Person bending anteriorly**. This is the only movement that does not involve changing position.