Bacterial flagellum is composed of

Options

A. Basal body and filament
B. Hook and filament
C. Basal body, hook and filament
D. Basal body, fimbriae and filament

Answer

To answer the question about the composition of a bacterial flagellum, we can break down the information provided in the video transcript into clear steps:

### Step-by-Step Solution:

1. **Identify the Structure of the Bacterial Flagellum**:
- The bacterial flagellum consists of three main parts: the basal body, the hook, and the filament.

2. **Describe the Basal Body**:
- The basal body is the portion of the flagellum that is anchored in the bacterial cell membrane. It serves as the motor that drives the rotation of the flagellum.

3. **Explain the Hook**:
- The hook is a short, curved structure that connects the basal body to the filament. It acts as a flexible coupling that allows the filament to rotate.

4. **Define the Filament**:
- The filament is the long, whip-like structure that extends from the hook. It is the part of the flagellum that propels the bacterium through its environment.

5. **Identify the Composition of the Filament**:
- The filament is primarily composed of a protein called flagellin. This protein forms a helical structure that contributes to the flagellum's ability to move.

6. **Summarize the Components**:
- Thus, the bacterial flagellum is composed of:
- Basal body
- Hook
- Filament (made of flagellin)

### Final Answer:
The bacterial flagellum is composed of the basal body, hook, and filament (which is made of the protein flagellin).

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