Plasmids are found in

Options

A. Bacteria
B. Yeast
C. Viruses
D. (1) and (2)

Answer

**Step-by-Step Solution:**

1. **Definition of Plasmids**:
- Plasmids are small, circular DNA molecules that are separate from chromosomal DNA. They are often referred to as extra-chromosomal DNA because they exist outside of the main chromosome in a cell.

2. **Characteristics of Plasmids**:
- Plasmids are typically circular in shape and can replicate independently of chromosomal DNA. They are not involved in the normal processes of cell division but can carry genes that provide advantages to the host organism, such as antibiotic resistance.

3. **Occurrence of Plasmids**:
- Plasmids are predominantly found in prokaryotic organisms, specifically bacteria. They can also be found in some eukaryotic organisms, such as yeast.

4. **Exclusion of Viruses**:
- Viruses do not contain plasmids. Instead, they are composed of genetic material (either DNA or RNA) surrounded by a protein coat. They do not have the structure or function of plasmids.

5. **Conclusion**:
- Therefore, the correct answer to the question "Where are plasmids found?" is that they are found in bacteria and yeast, but not in viruses.

**Final Answer**: Plasmids are found in bacteria and yeast (eukaryotes), but not in viruses.

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