Which of the following assists in the locomotion of the organism stated ?

Options

A. Pedicellaria of starfish
B. Epithelium of Pheretima
C. Trichocysts of Paramecium
D. Posterior sucker of Hirudinaria

Answer

To solve the question "Which of the following assists in the locomotion of the organism stated?" we need to analyze each option provided and determine if it plays a role in locomotion for the specified organism.

### Step-by-Step Solution:

1. **Analyze the First Option: Pardecelaria**
- Pardecelaria is described as a small claw-shaped appendage with movable jaws found in sea stars (starfish).
- While it may assist in feeding, it does not primarily assist in locomotion.
- **Conclusion**: This option is incorrect for locomotion.

2. **Analyze the Second Option: Apithelium of Pharytema**
- Pharytema refers to a genus of organisms, and locomotion in these organisms is primarily assisted by circular and longitudinal muscles.
- The term "Apithelium" seems to be a misinterpretation or typo, as it does not directly relate to locomotion.
- **Conclusion**: This option is also incorrect for locomotion.

3. **Analyze the Third Option: Trichocyst of Paramecium**
- Trichocysts are structures found in the cortex of Paramecium, which are primarily involved in defense and not locomotion.
- Paramecium moves using cilia, not trichocysts.
- **Conclusion**: This option is incorrect for locomotion.

4. **Analyze the Fourth Option: Posterior Sucker of Erudinaria**
- The posterior sucker in Erudinaria (a genus of leeches) is specifically adapted for locomotion.
- It helps the organism attach to surfaces and move effectively through its environment.
- **Conclusion**: This option is correct as it assists in locomotion.

### Final Answer:
The correct answer is **Option 4: Posterior sucker of Erudinaria**.

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