Transfer of DNA from one bacteria to another by contact is known as

Options

A. conjugation
B. transformation
C. transduction
D. transcription

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the method of DNA transfer between bacteria that occurs through direct contact.

2. **Identifying the Options**: The options given are:
- A) Conjugation
- B) Transformation
- C) Transduction
- D) Transcription

3. **Eliminating Incorrect Options**:
- **Transcription**: This is the process of synthesizing RNA from DNA and does not involve the transfer of DNA between bacteria. Therefore, we can eliminate this option.
- **Transduction**: This process involves the transfer of DNA from one bacterium to another via a bacteriophage (a virus that infects bacteria). There is no direct contact between the two bacteria in this process, so we can eliminate this option as well.
- **Transformation**: This process involves a bacterium taking up free DNA from its environment. It does not require direct contact between two bacteria, so we can eliminate this option too.

4. **Identifying the Correct Option**:
- **Conjugation**: This is the process where two bacteria come into direct contact, usually through a structure called a pilus, allowing for the transfer of DNA from one bacterium to another. This matches the requirement of the question.

5. **Conclusion**: The transfer of DNA from one bacterium to another by contact is known as **Conjugation**.

**Final Answer**: Conjugation

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