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

Kinetoplastids• Kinetoplastids– Have a single, large mitochondrion thatcontains an organized mass of DNA called akinetoplast• The parasitic kinetoplastid Trypanosoma– Causes sleeping sickness in humansFigure 28.79 µmCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsEuglenids• Euglenids– Have one or two flagella that emerge from apocket at one end of the cell• Alveolates have sacs beneath the plasmamembraneLong flagellumEyespot: pigmentedorganelle that functionsas a light shield, allowinglight from only a certaindirection to strike thelight detectorShort flagellumLight detector: swelling near thebase of the long flagellum; detectslight that is not blocked by theeyespot; as a result, Euglena movestoward light of appropriateintensity, an important adaptationthat enhances photosynthesis0.2 µmFlagellumAlveoliEuglena (LM)5 µmNucleusContractile vacuolePlasma membranePellicle: protein bands beneaththe plasma membrane thatprovide strength and flexibilityFigure 28.8(Euglena lacks a cell wall)Copyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsChloroplastParamylon granuleFigure 28.9Copyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsDinoflagellates• Dinoflagellates• Rapid growth of some dinoflagellates– Are a diverse group of aquatic photoautotrophsand heterotrophs– Is responsible for causing “red tides,” whichcan be toxic to humans– internal plates of cellulose• Two flagella– Make them spin as they move through thewaterCopyright © 2005 Pearson Education, Inc. publishing as Benjamin CummingsCopyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings3