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
4How Many Kingdoms? Extant 8 5 3 Extinct 2 Long Time with 1 ArchaebacteriaArchezoansProtozoansChrysophytesBrown AlgaeRed algaeGreen AlgaeBryophytesTracheophytesSlime MoldsMulticellular AnimalsMyxozoansTrue FungiBacteriaEuglenoids853Extinct21Long Time withProkaryotes onlyOriginal Cell
5Euglenozoa Flagellated protists which can be photosynthetic Odd featuresProtein pellicle instead of cell wallOdd mitochondria (discoid cristae)Chromosomes condensed during interphase400 species (many more likely unknown parasites!)Two sub-phyla:Kinetoplasta (Trypanosoma gambiense) sleeping sicknessEuglenoida (Euglena) photosynthetic, chlorophyll a,b, paramylum
6Trypanosoma gambiense Trypanosoma gambienseBlood-borne parasiteNucleusFlagellated undulating cellFlagellumVectored by Tsetse fly between alternate hostsChemical agent causes African sleeping sickness
7Euglena gracilis Posterior extension Mitochondrion Pyrenoid Nucleus ChloroplastsParamylon grainProtein pellicle(striations)Contractile vacuoleEyespotAnterior invaginationWith internal short flagellumLong flagellum rooted here also(not shown)
8How Many Kingdoms? Extant Euglenoid mitochondria are unique! Multicellular AnimalsMyxozoansProtozoansTracheophytesBryophytesTrue FungiSlime MoldsRed algaeBrown AlgaeGreen AlgaeChrysophytesEuglenoidsArchezoansArchaebacteriaBacteriaChlorophytealgalendosymbiosisEuglenoid mitochondria are unique!Eukaryotes ARE Chimeras!CyanobacteriumendosymbiosisFor euglenoids, the chloroplast is a secondary endosymbiosis.ExtinctEubacteriumendosymbiosisThough sketched here as single events, these endosymbioses were very likely multiple events!Original Cell
9Scarcodine and Actinopod Protozoans Domain EukaryaKingdom ProtistaPhylum Sarcodina
10Amoeba proteus A freshwater amoeboid protist Engulfing a Staurastrum green algaAmoeba proteusFood vacuolesContractile vacuoleThe pseudopodia assist in locomotion and phagocytosis, but they also secrete proteolytic enzymes to digest particles outside the cell.NucleusMitochondriaPseudopodiaMarine relatives, the foraminifera, secrete calcareous shells, contributing to reefs and sands.
11Arcella gibbosa Freshwater amoeboid protist Chitinous test Hyaline connections to the cellFood vacuoles obviousSome have two or more nucleiPseudopodia protrude from the testFeeding here upon green algae
12Orbulina universa, or Globigerina bulloides A living foraminiferan demonstrates its many and delicate pseudopodiaIn addition to capturing food items, the foram also receives nutrients from its endosymbionts
13Actinosphaerium eichhorni This organism is an actinopod.Its axipods are stiff projections rather than delicate pseudopodia.The axipods are stiffened primarily by silicates taken from the water.It is related to many radiolarians which are known only from their tests fossilized in silicate deposits.