The structure that help some bacteria to attach to rocks and host tissues are

Options

A. rhizoids
B. fimbriae
C. mesosomes
D. holdfast

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks for the structure that helps some bacteria attach to rocks and host tissues.

2. **Identify the Options**: The options provided are:
- Rhizoids
- Fimbriae
- Mesosomes
- Holdfasts

3. **Analyze Each Option**:
- **Rhizoids**: These are structures found in plants, not in bacteria. Therefore, this option is incorrect.
- **Fimbriae**: These are hair-like appendages found on the surface of many bacteria. They help bacteria adhere to surfaces, including rocks and host tissues. This option is likely correct.
- **Mesosomes**: These are invaginations of the bacterial cell membrane and are involved in various cellular processes, but they do not serve the function of attachment. Thus, this option is incorrect.
- **Holdfasts**: While holdfasts are structures that help some organisms attach to surfaces, they are not typically found in bacteria. Therefore, this option is also incorrect.

4. **Conclusion**: After analyzing all the options, the correct answer is **Fimbriae**. These structures are specifically adapted for attachment in bacteria.

**Final Answer**: The structure that helps some bacteria to attach to rocks and host tissues is **Fimbriae**.

---