Concept
Bacteriophage
Virus that infects bacteria
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High-yield clue
A bacteriophage is a host-specific bacterial virus with a capsid head and tail fibers that inject genetic material into a bacterium; it is the vehicle behind transduction.
Overview
A virus that infects and replicates within bacteria, typically with a protein capsid head, tail, and tail fibers that inject nucleic acid into the host. Phages underlie transduction and lysogenic gene transfer.
Classification
- Bacterial virus
- Capsid head with tail structure
- DNA or RNA genome
- Host-specific
Lab & identification clues
- Plaque-forming-unit vocabulary
- Tail-fiber host-attachment concept
- Phage-typing identification vocabulary
Associations
- Vector for transduction
- Source of lysogenic conversion
- Highly host-specific attachment
Commonly confused with
- Animal virus
- Plasmid
Your notes
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.