🦠microbiology review

Bacterial genomes

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Bacterial genomes are the complete set of genetic material present within a bacterium, typically consisting of a single circular chromosome and sometimes plasmids. They encode all the information necessary for the bacterium's growth, reproduction, and function.

5 Must Know Facts For Your Next Test

  1. Bacterial genomes are generally smaller and less complex than eukaryotic genomes.
  2. Most bacterial genomes consist of a single circular DNA molecule, though some bacteria have linear chromosomes or additional plasmids.
  3. Horizontal gene transfer is a significant mechanism in bacteria that contributes to genetic diversity and antibiotic resistance.
  4. The size of bacterial genomes can range from around 160,000 base pairs to over 12 million base pairs.
  5. Bacterial genome sequencing has revolutionized microbiology by enabling rapid identification and characterization of bacterial species.

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