Bacteria reproduce sexually by

Options

A. endospore
B. conidia
C. binary fission
D. transformation

Answer

To answer the question "Bacteria reproduce sexually by," we need to analyze the options provided and understand the modes of reproduction in bacteria.

### Step-by-Step Solution:

1. **Understanding Bacterial Reproduction**:
- Bacteria can reproduce in two main ways: asexual reproduction and sexual reproduction.
- Asexual reproduction does not involve the fusion of gametes, while sexual reproduction involves the fusion of genetic material from two different bacteria.

2. **Evaluating the Options**:
- **Endospore**: This is a method bacteria use to survive in harsh conditions, not a method of sexual reproduction. It is a form of asexual reproduction.
- **Conidia**: This is a type of asexual reproduction seen in fungi, not typically in bacteria. Thus, it is not a correct option for bacterial sexual reproduction.
- **Binary Fission**: This is the most common method of asexual reproduction in bacteria, where a single bacterium divides into two identical daughter cells. Therefore, this option is incorrect for sexual reproduction.
- **Transformation**: This process involves the uptake of foreign genetic material (DNA) from the environment by a bacterium. This transfer of genetic material can lead to genetic recombination, which is a form of sexual reproduction.

3. **Conclusion**:
- Based on the analysis, the correct answer to the question is **Transformation**, as it involves the transfer of genetic material and can lead to genetic variation, which is characteristic of sexual reproduction.

### Final Answer:
Bacteria reproduce sexually by **Transformation**.