2The Organism as a Unit of Life Looking Back at Bio 115The Organism as a Unit of LifeCellular Structure (cell = unit of life)…one or many!Metabolism = Homeostasis (PSN, Resp, N2fix, ferment, etc.)Growth = irreversible change in sizeReproduction…failure = extinctionAcclimatization-short term responses = behaviorAdaptation-long term responses = evolution
6How Many Kingdoms? Extant 8 Still needs refining! Protista appears 5 3 Multicellular AnimalsMyxozoansProtozoansTracheophytesBryophytesTrue FungiSlime MoldsRed algaeBrown AlgaeGreen AlgaeChrysophytesEuglenoidsArchezoansArchaebacteriaBacteriaProtistarefined8Still needs refining!Protista appears53Extinct21Long Time withProkaryotes onlyOriginal Cell
7How Many Kingdoms? Extant Eukaryotes ARE Chimeras! Extinct Multicellular AnimalsMyxozoansProtozoansTracheophytesBryophytesTrue FungiSlime MoldsRed algaeBrown AlgaeGreen AlgaeChrysophytesEuglenoidsArchezoansArchaebacteriaBacteriaEukaryotes ARE Chimeras!CyanobacteriumendosymbiosisExtinctEubacteriumendosymbiosisThough sketched here as single events, these endosymbioses were very likely multiple events!Original Cell
8Archezoans “Protozoan parasites without mitochondria or Golgi” Oldest nucleated cellsDiverged from other Eukaryotes 2bybp… prior to ER and Golgi evolutionLack peroxisomesRibosomes are 70S but NOT 80S400 species (many more likely unknown parasites!)Three phyla:Archaeamoebae/Pelobiontida (Pelomyxa)Metamonada (Giardia)Microsporidia
9Pelomyxa palustris Pseudopodia Endosymbiotic bacteria Free-living in freshwater sediment (microaerophilic)Phagocytosis activeUroidAccumulate glycogen reservesAt least 3 species of endosymbiont in each cell…two species are methanogenic archaeons!Glycogen bodyAnterior uroid (macropseudopodium) for amoeboid movementVacuolesSmaller pseudopodia do not enlarge
10Reproduction: Mitosis of nucleus Cytokinesis by furrowing Nuclei “Daughter” AmoebaWhat would you suggest has been a large component of this individual’s phagocytosis diet?
11Giardia lamblia Diplomonad intestinal parasite 2 nuclei in anterior of cellMotility2 anterior flagella4 ventral flagella2 posterior flagellaVentral disc ridges provide adhesion to host
12Giardia lambliaParasite cyst in feces of beaver released into watershedHumans ingest water… cyst grows into trophozoite (shown)… parasite attaches to intestinal wallParasite proliferates and, as digestion continues, are torn from lining leading to bloody diarrhea
13Giardia lambliaParasite cyst showing environmentally-stable wall of cyst, ectoplasm, endoplasm with 2 of 4 nucleiTrophozoites in various planes of section showing nuclei, flagellae, etc.Adhesive disc from ventral surface of trophozoite.
14Nosema locustaeMicrosporidian parasite of locusts, grasshoppers and cricketsUsed as a form of biological control
15Nosema algerae Microsporidian parasite of mosquitoes Wet Mount Scanning EMTransmission EM
16Nosema apis Microsporidian parasite of honeybees Swollen intestinal system, loss of banding patternsDiarrhea, winterkillNosema apisControl by Fumagillin-B fromAspergillus fumigatus