Microsoft PowerPoint - 28- protists revised.pdf - NSD Main

• A sample of protist diversityEndosymbiosis in Eukaryotic Evolution• There is now considerable evidence– That much of protist diversity has its origins inendosymbiosisTable 28.1Copyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings• The plastid-bearing lineage of protists– Evolved into red algae and green algaeDiplomonads• Diplomonads– Have two nuclei and multiple flagella• On several occasions during eukaryoticevolution– Red algae and green algae underwentsecondary endosymbiosis, in which theythemselves were ingestedFigure 28.5a(a) Giardia intestinalis, a diplomonad (colorized SEM)5 µmCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsParabasalids• Parabasalids include trichomonads– Which move by means of flagella and anundulating part of the plasma membraneFlagella• Euglenozoans have flagella with a uniqueinternal structure– Is the presence of a spiral or crystalline rod ofunknown function inside their flagellaUndulating membrane 5 µmFigure 28.5b (b) Trichomonas vaginalis, a parabasalid (colorized SEM)Copyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings2