Prokaryotic flagella possess

Options

A. Helically arranged protein molecule
B. "9+2" membran enclosed structure
C. Unit membrane enclosed fibre
D. Protein membrane enclosed fibre

Answer

### Step-by-Step Solution:

1. **Understanding Prokaryotic Flagella**: Prokaryotic flagella are hair-like structures that enable movement in prokaryotic cells (like bacteria). Unlike eukaryotic flagella, they have a different structure and composition.

2. **Composition of Prokaryotic Flagella**: Prokaryotic flagella are primarily composed of a protein called flagellin. This protein is arranged in a helical structure, forming a long, thin filament.

3. **Absence of Membrane**: One of the key characteristics of prokaryotic flagella is that they are not enclosed by a membrane. This differentiates them from eukaryotic flagella, which have a membrane surrounding their structure.

4. **Comparison with Eukaryotic Flagella**: Eukaryotic flagella have a distinct 9+2 arrangement of microtubules (nine doublet microtubules surrounding two central microtubules). This structure is not present in prokaryotic flagella.

5. **Correct Answer**: Based on the above points, the prokaryotic flagella possess helically arranged protein molecules (flagellin), which form a hollow cylinder, and do not have a membrane.

### Final Answer:
Prokaryotic flagella possess helically arranged protein molecules (flagellin).

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