Bacterium in which conjugation was discovered is

Options

A. Bacillus subtilis
B. Escherichia coli
C. Salmonella typhosa
D. Streptococcus nigricans

Answer

**Step-by-Step Solution:**

1. **Understanding Conjugation**: Conjugation is a process in bacteria where genetic material is transferred from one bacterium to another. This process is essential for genetic diversity among bacterial populations.

2. **Role of Pili**: The transfer of genetic material during conjugation occurs through structures called pili (singular: pilus). These are hollow appendages made of protein that facilitate the connection between two bacterial cells.

3. **Types of Bacteria**: Conjugation primarily occurs in gram-negative bacteria, which have a specific cell wall structure that allows for the formation of pili.

4. **Identifying the Bacterium**: The bacterium in which conjugation was first discovered is Escherichia coli, commonly known as E. coli. This discovery was made by scientists Joshua Lederberg and Edward Tatum.

5. **Conclusion**: Therefore, the correct answer to the question "Bacterium in which conjugation was discovered is" is Escherichia coli (E. coli).

**Final Answer**: Escherichia coli (E. coli)

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