Organismic ch 26

• LUCA


  Last Universal Common Ancestor
• Three Domains of Life

  • Eubacteria
  • Archaea
  • Eukarya
• Endosymbiotic Theory


  Origin of mitochondria and chloroplasts
• Eukaryotic Compartmentalization


  Nucleus, organelles, etc.
• Prokaryote Domination


  • Bacteria/archaea for 1 billion years
• Emergence of Eukaryotes in fossil record

  1.5 billion years ago
• Endomembrane System


  Compartmentalized eukaryotic cell
• Multicellularity


  • Specialization through cell types/tissues
• Opisthokonts


  Unicellular ancestor gave rise to animals
• Cambrian Explosion - Rapid radiation of animal life

  543-488 million years ago
• Eukaryotic Supergroups


  • Archaeplastida
  • SAR
  • Excavata
  • Amoebozoa
• Eukaryotes arose and diversified

  Proterozoic Eon
• Snowball Earth


  Periods of global glaciation prior to Cambrian
• Dictyostelium


  • Slime mold forms transient multicellular stage
• Red/Green/Brown Algae


  • Origins of independent multicellularity
• Meiosis


  Increased genetic diversity in eukaryotes vs prokaryotes
• Stomata


  Plant openings regulating gas exchange
• Crossing Over


  Exchange of DNA during meiosis
• Mitochondria


  Aerobic respiration organelle of eukaryotes
• Chloroplasts


  Photosynthesis organelle of plants/algae
• Photosynthesis


  Created oxygen-rich atmosphere/ozone layer
• Lungs vs Gills


  Strategies for terrestrial vs aquatic gas exchange