Plasmids are autonomously replicating mini chromosomes found in :

Options

A. Bacteriophage lambda
B. Leishmania donovani
C. Escherichia coli
D. Paramecium coudatum

Answer

To solve the question regarding where plasmids, which are autonomously replicating mini chromosomes, are found, we can follow these steps:

### Step-by-Step Solution:

1. **Understand what plasmids are**:
- Plasmids are small, circular, double-stranded DNA molecules that are distinct from a cell's chromosomal DNA. They can replicate independently within a cell.

2. **Identify the options given**:
- A. Bacteriophage lambda
- B. Leishmania donovani
- C. Escherichia coli
- D. Paramecium chordatum

3. **Analyze each option**:
- **A. Bacteriophage lambda**: This is a virus that infects bacteria and does not contain plasmids.
- **B. Leishmania donovani**: This is a protozoan parasite and does not typically contain plasmids.
- **C. Escherichia coli**: This is a type of bacteria that is well-known for containing plasmids. Plasmids in E. coli can carry genes that confer advantageous traits, such as antibiotic resistance.
- **D. Paramecium chordatum**: This is a ciliate protozoan and does not have plasmids.

4. **Conclude the correct answer**:
- Based on the analysis, the only option that is known to contain plasmids is **C. Escherichia coli**.

### Final Answer:
The correct answer is **C. Escherichia coli**.