Question

Plasmids occur in

• A. Mycoplasma
• B. Prions
• C. Bacteria
• D. Virus

Answer 1

The Correct Option is C

• Plasmids are small, circular extra-genomic structures found in bacteria. 
• They carry double-stranded DNA molecules distinct from the bacterial genome.
•  These structures possess a self-replicating nature, allowing them to multiply independently without cellular support. 
• Plasmids typically contain 1,000 to 200,000 base pairs of DNA.

While not essential for bacterial survival as they harbor extrachromosomal material, plasmids aid bacteria in adapting to environmental changes.Additionally, they facilitate processes such as conjugation, enabling bacteria to exchange genetic material with other bacterial cells. Plasmids can also confer antibiotic resistance to bacteria by providing genetic codes for resistance mechanisms.

In contrast, other microorganisms like mycoplasma, viruses, and prions lack plasmids as extra-genomic structures within their cellular makeup.

Answer 2

A plasmid is a small, circular DNA molecule that replicates independently of chromosomal DNA and is primarily found in bacteria. Therefore, the correct option is 'Bacteria'.