Classifying Prokaryotes

• Biologists divide prokaryotes in two of the three domains of life:

  • Archase: contains all the Archaebacteria
  • Bacteria: contain all the Eubacteria
  • The third domain of life contains all of the eukaryotic organisms
• Eubacteria include organisms that live in a variety of environments including:

  • fresh and saltwater, on land, in and on the human body
  • the group that can cause disease in living organisms
• Archaebacteria can live in extreme environments:

  • Methanogens live in oxygen-free environments, such as thick mud and animal digestive tracts
  • Some live in salty environments or in hot springs where water temperatures approach the boiling point
  • Ex: halophiles and thermophiles