Sexual reproduction in eubacteria takes place by

Options

A. Transformation
B. Transduction
C. Conjugation
D. All the above.

Answer

### Step-by-Step Solution:

1. **Understanding Eubacteria**: Eubacteria, also known as true bacteria, are prokaryotic organisms that do not undergo typical sexual reproduction. This is primarily because they do not form gametes and do not undergo meiosis.

2. **Absence of Typical Sexual Reproduction**: In Eubacteria, typical sexual reproduction is absent due to the lack of gamete formation and meiosis. This means that they do not reproduce in the same way that many eukaryotic organisms do.

3. **Gene Recombination**: Although Eubacteria do not reproduce sexually in the traditional sense, they can exchange genetic material through processes that resemble sexual reproduction. This process is known as gene recombination.

4. **Processes of Gene Recombination**: There are three main processes through which gene recombination occurs in Eubacteria:
- **Transformation**: This is the uptake of free DNA from the environment by a bacterial cell.
- **Transduction**: This involves the transfer of DNA from one bacterium to another via a bacteriophage (a virus that infects bacteria).
- **Conjugation**: This is the direct transfer of DNA between two bacteria that are temporarily joined together by a structure called a conjugation tube.

5. **Conclusion**: Since all three processes (transformation, transduction, and conjugation) are mechanisms through which Eubacteria can exchange genetic material, they can be considered as forms of sexual reproduction in a broader sense. Therefore, the correct answer to the question is **D) All of the above**.