Concept
Plasmid
Extrachromosomal self-replicating DNA loop
PLAZ-mid
High-yield clue
Plasmids are the classic mobile carriers of antibiotic-resistance genes that spread horizontally between cells.
Overview
A small circular double-stranded DNA molecule that replicates independently of the bacterial chromosome and can carry accessory genes such as antibiotic resistance or virulence factors. It is a core study concept for how resistance spreads between bacteria.
Classification
- Extrachromosomal DNA
- Circular double-stranded
- Autonomously replicating
- Often transmissible
Lab & identification clues
- R-plasmid resistance-gene vocabulary
- F (fertility) plasmid concept
- Copy-number and incompatibility vocabulary
Associations
- Antibiotic-resistance gene carriage
- Transferable via conjugation
- Virulence-factor gene carriage
Commonly confused with
- Bacterial chromosome
- Transposon
Frequently asked questions
What is Plasmid?
A small circular double-stranded DNA molecule that replicates independently of the bacterial chromosome and can carry accessory genes such as antibiotic resistance or virulence factors. It is a core study concept for how resistance spreads between bacteria.
What is the high-yield clue for Plasmid?
Plasmids are the classic mobile carriers of antibiotic-resistance genes that spread horizontally between cells.
What is Plasmid associated with?
Plasmid is associated with Antibiotic-resistance gene carriage, Transferable via conjugation, and Virulence-factor gene carriage.
What is Plasmid commonly confused with?
Plasmid is commonly confused with Bacterial chromosome and Transposon.
Original microbiology concept summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC/WHO topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment selection, infection-control instructions, or specimen-handling guidance.