Which of the following is not a structure of prokaryotic flagella ?

Options

A. Filament
B. centriole
C. Hook
D. Basal body

Answer

To determine which of the following is not a structure of prokaryotic flagella, we need to analyze the components of prokaryotic flagella and compare them to the options given.

### Step-by-Step Solution:

1. **Understanding Prokaryotic Flagella**:
Prokaryotic flagella are appendages that help in the movement of prokaryotic cells (like bacteria). They are composed of three main parts: the filament, the hook, and the basal body.

2. **Identifying the Structures**:
- **Filament**: This is the long, whip-like structure that extends from the cell surface and is responsible for the actual movement.
- **Hook**: This connects the filament to the basal body and allows for the rotation of the filament.
- **Basal Body**: This is the part that anchors the flagellum to the cell membrane and is embedded within it.

3. **Evaluating the Options**:
The options provided are:
- **Filament**: This is a correct structure of prokaryotic flagella.
- **Centriole**: This is not a structure of prokaryotic flagella; it is found in animal cells and is involved in cell division.
- **Hook**: This is a correct structure of prokaryotic flagella.
- **Basal Body**: This is a correct structure of prokaryotic flagella.

4. **Conclusion**:
Since the centriole is not part of prokaryotic flagella and is instead associated with animal cells, the answer to the question is **centriole**.

### Final Answer:
**Centriole** is not a structure of prokaryotic flagella.

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