Section 18-3: Building the Tree of Life In Linneauss time organisms were either plants or animals Animals moved from place to place, used food Plants green, got energy from sun, did not move Does not reflect diversity New data changed this idea, and it is still changing Kingdom Archaebacteria and Kingdom Eubacteria more genetically different from each other and from eukaryotes Higher taxonomic group domain Domain Bacteria (Kingdom Eubacteria) Domain Archae (Kingdom Archaebacteria) Domain Eukarya (Kingdoms Protista (not monophyletic), Fungi, Plantae, Animalia) Modern evolutionary classification constantly and rapidly changing Tree of life shows current hypotheses All unicellular, prokaryotic Kingdom Eubacteria (true bacteria) Thick, rigid cell walls containing peptidoglycan Ecologically diverse some photosynthetic, some parasitic, some anaerobic, some aerobic Kingdom Archaebacteria Unicellular, prokaryotic Some live in extreme environments (some can only survive without oxygen) No peptidoglycan in cell walls membranes contain unusual lipids All organisms with nuclei Kingdom Protista Unicellular eukaryotes Catchall kingdom At least 5 clades Only one group (brown algae) that is mutlticellular Some photosynthetic, some heterotrophic Some resemble fungi, plants, animals Kingdom Fungi Heterotrophic, cells walls made of chitin Most feed on dead/decaying organic matter Extracellular digestion Includes mushrooms (multicellular) and yeasts (unicellular) Kingdom Plantae Multicellular, cells walls of cellulose, autotrophic Chlorophyll Nonmotile Green algae, mosses, ferns, conifers, flowering plants Kingdom Animalia Multicellular, heterotrophic No cell wall Most motile in some way