Domains and Kingdoms

Domain

• largest category
• bacteria, archaea, eukarya

Bacteria

• prokaryotic
• unicellular
• cell walls thick + rigid with peptidoglycan
• some photosynthesize
• some need oxygen, some die from it
• ecologically diverse, range from free-living soil ones to deadly parasites
• includes Kingdom Eubacteria

Peptidoglycan

polymer of sugar and amino acid that form mesh layer over cell wall

Archaea

• prokaryotic
• unicellular
• cell walls without peptidoglycan
• live in extreme environments
  • volcanic hot springs, black organic mud, etc.
• many of these bacteria can survive without oxygen
• includes Kingdom Archaebacteria

Eukarya

• all organisms with nucleus
• includes 4 major Kingdoms: Protista, Fungi, Plantae, Animalia

Kingdoms

• 2nd largest group
• includes 6 Kingdoms: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia

Eubacteria

• prokaryote
• unicellular
• autotrophs or heterotrophs
• live everywhere
• “true bacteria”

Archaebacteria

• prokaryote
• unicellular
• autotrophs or heterotrophs
• live in extreme conditions
• chemically different from Eubacteria

Protista

• eukaryotes
• most unicellular, some multicellular
• photosynthetic or heterotrophic
• don’t fit in anywhere else so diverse
  • protozoa, fungus-like, algae, etc.

Fungi

• eukaryotes
• multicellular
• heterotrophs
• cell walls of chitin
• feed on dead or decaying matter

Plantae

• eukaryotes
• multicellular
• autotrophs/photosynthesis
• cell walls with cellulose
• non-motile (non-moving)

Animalia

• eukaryotes
• multicellular
• heterotrophs
• no cell walls
• motile (moving)
• largest known kingdom

Tree of All Life

• shows current hypotheses about evolutionary relationships among taxa within 3 Domains