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Protists

Protists. By: Lauren Kelly, Katie Chicojay, Jessie Sandberg, and Kirsten Gronlund. Eukaryotes . evolved between 2 to 2.25 billion years ago chromosomes located in membrane-enclosed nucleus organelles membrane-bound specialized form and function generally larger than prokaryotic cells.

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Protists

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  1. Protists By: Lauren Kelly, Katie Chicojay, Jessie Sandberg, and Kirsten Gronlund

  2. Eukaryotes • evolved between 2 to 2.25 billion years ago • chromosomes located in membrane-enclosed nucleus • organelles • membrane-bound • specialized form and function • generally larger than prokaryotic cells

  3. Protista Kingdom • eukaryotic • most diverse kingdom- all organisms that are not plants, animals, or fungi • paraphyletic- not grouped by evolutionary relatedness • most are aquatic • may live anywhere damp

  4. Biology of Protists • cyst formation • forms when a protist is in harsh environment • dormant form of cell with resistant outer covering • locomotion • whip-like flagella • blob-like appendages • cilia • structure • most unicellular • some colonial  • some multicellular •  Nutritionally diverse • photoautotrophs • heterotrophs • mixotrophs • reproduction • sexually          (meiosis & syngamy) • asexually

  5. Theory of Endosymbiosis • Endosymbiosis - Process in which a unicellular organism engulfs another cell • Engulfed cell becomes an endosymbiont and ultimately an organelle in host • Secondary Endosymbiosis - Process in which the product of primary endosymbiosis is itself engulfed and retained by another eukaryotic cell • Engulfed cell becomes an endosymbiont

  6. Evidence of Endosymbiosis 1. All eukaryotes have mitochondria or had them in the past 2. Mitochondria and chloroplasts contain DNA but lack      nucleus 3. Mitochondria and chloroplasts contain their own      ribosomes 4. Mitochondria and chloroplasts are able to self replicate by      binary fission 5. Mitochondria and chloroplasts     move freely within the cell

  7. Primary and Secondary Endosymbiosis

  8. Lineages of Prostists • Flagellated Protozoans • Alveolates • Stramenopiles • Red Algae • Green Algae • Amoebozoans

  9. Flagellated Protozoans • Single-celled organisms • lack a cell wall • one or more flagella • pellicle layer of protein under plasma membrane (shape) • Reproduce asexually - binary fission •  Different types of flagellated protozoans: • Diplomonads • Parabasalids • Kinetoplastids • Euglenoids • Radiolarians • Foraminiferans Giardia lamblia

  10. Alveolates • Characterized by membrane bound sacs (aveoli) under the plasma membrane. • The function of the aveoli are unknown.  Some hypothesis they help to stabilize the cell's surface or regulate the cell's water and ion content • Includes flagellates (dinoflagellates), parasites (apicomplexans) and cilla motive protists (ciliates). Plasmodium vivax

  11. Stramenopiles • Stramenopiles contains • several groups of heterotrophs  • some groups of algae • shared characteristic: flagellum- hairlike projections that help with motion and feeling • most have both a hairy and smooth flagellum • always paired together • 2 flagella=motile reproductive cells Synura petersenii

  12. Red Algae • red color derived from accessory pigment phycobili • allows absorption of blue and green light, which penetrate farther into water • most abundant type of large algae in tropical oceans • also found in freshwater and on land • mostly multicellular • diverse life cycles • often alternation of generations • no flagellated life stage Bonnemaisonia hamifera

  13. Green Algae • aquatic autotrophs • chloroplasts similar to those of plants • contains two groups: • chlorophytes • most live in freshwater, some in marine environments • simplest chlorophytes are biflagellated, unicellular • more complex/larger chlorophytes evolve through: • formation of colonies • repeated nucleic division without cytokinesis • formation of true multicellular forms- cell division and differentiation • complex life cycles • sexual and asexual reproductive stages • most reproduce sexually • charophyceans • most closely related to land plants Chlamydomonas nivalis

  14. Amoebozoans • characterized by lobe-shaped pseudopodia • 3 types: • Gymnamoebas • heterotrophs • Entamoebas • parasites • Slime Molds • produce fruiting bodies for spore dispersal • Plasmodial Slime Molds • plasmodium life stage • unicellular, many diploid nuclei • Cellular Slime Molds • generally, cells function individually • lack of food- cells group, function as unit Physarum polycephalum

  15.  Works Cited http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb2pg1_files/Physarum_polycephalum.jpg http://www.am.dodea.edu/NY_VA/dahlgren/work/Lang_arts_MsW/Protist/media/protist.png http://www.ebi.ac.uk/microarray/biology_intro_files/cell.jpe http://www.biologycorner.com/resources/parameciums.jpg http://kdhellner.tripod.com/sitebuildercontent/sitebuilderpictures/.pond/protist.jpg.w300h223.jpg http://protist.i.hosei.ac.jp/pdb/images/ciliophora/Carchesium/sp_3b.jpg http://endosymbiotichypothesis.files.wordpress.com/2010/09/endosymbiosis_c_la_784.jpg Campbell/Reece 7th Edition Biology http://www.scientificamerican.com/article.cfm?id=when-did-eukaryotic-cells 

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