What is false about plasmids ?

Options

A. It is must for normal life of bacterium
B. It confers property of drug resistance
C. It confers property of toxigenicity
D. It endows the host with ability to conjugate

Answer

To determine which statement about plasmids is false, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Plasmids**:
- Plasmids are small, circular, double-stranded DNA molecules that are separate from chromosomal DNA in bacteria. They are considered extra-chromosomal DNA.

2. **Analyzing Option A**:
- **Statement**: "It is must for normal life of bacterium."
- **Analysis**: This statement is false. Bacteria can live and function normally without plasmids. Therefore, this option is incorrect.

3. **Analyzing Option B**:
- **Statement**: "It confers property of drug resistance."
- **Analysis**: This statement is true. Many plasmids carry genes that provide bacteria with resistance to antibiotics, making this option correct.

4. **Analyzing Option C**:
- **Statement**: "It confers property of toxigenicity."
- **Analysis**: This statement is also true. Certain plasmids can carry genes that enable bacteria to produce toxins, thus conferring toxigenicity. This option is correct.

5. **Analyzing Option D**:
- **Statement**: "It endows the host with ability to conjugate."
- **Analysis**: This statement is true as well. Some plasmids contain genes that facilitate conjugation, a process of genetic exchange between bacteria. This option is correct.

6. **Conclusion**:
- After analyzing all options, the only false statement is **Option A**: "It is must for normal life of bacterium." Thus, the correct answer is Option A.

### Final Answer:
The false statement about plasmids is **Option A**: "It is must for normal life of bacterium."

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