Structures in bacteria that help in attachment to rocks in streams and host tissues are

Options

A. bristle like fibres that sprout out of the cell
B. composed of filament, hook and basal body
C. useful in cell motility
D. provide mechanical support to bacterial cell

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for structures in bacteria that assist in attachment to surfaces such as rocks in streams and host tissues.

2. **Analyzing the Options**:
- **Option 1**: "Bristle-like fibers that sprout out of the cell" - This describes structures known as **fimbriae** or **pili**, which are indeed used by bacteria to adhere to surfaces.
- **Option 2**: "Composed of filament, hook, and basal body" - This describes the structure of **flagella**, which are used for movement, not for attachment.
- **Option 3**: "Useful in cell motility" - This again refers to **flagella**, which are primarily involved in the movement of the bacteria.
- **Option 4**: "Provided mechanical support to the bacterial cell" - This is not accurate for attachment; it may refer to the cell wall structure but does not pertain to attachment mechanisms.

3. **Identifying the Correct Answer**: Based on the analysis, the correct answer is **Option 1**: "Bristle-like fibers that sprout out of the cell" (fimbriae), as they are specifically designed for attachment.

4. **Conclusion**: The structures in bacteria that help in attachment to rocks in streams and host tissues are fimbriae.

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