ProtistsBy: 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

o membrane-boundo specialized form and function

• generally larger than prokaryotic cells

Protista Kingdom• eukaryotic • most diverse kingdom- all organisms that are not plants,

animals, or fungi • paraphyletic- not grouped by evolutionary relatedness• most are aquatic

o may live anywhere damp

Biology of Protists • structure

o most unicellularo some colonial o some multicellular

•  Nutritionally diverseo photoautotrophs o heterotrophso mixotrophs

• reproductiono sexually 

        (meiosis & syngamy)o asexually

 

• cyst formationo forms when a protist is in

harsh environmento dormant form of cell with

resistant outer covering• locomotion

o whip-like flagellao blob-like appendageso cilia

• Endosymbiosis - Process in which a unicellular organism engulfs another cello 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 cello Engulfed cell becomes an endosymbiont

Theory of Endosymbiosis

Evidence of Endosymbiosis

1. All eukaryotes have mitochondria or had them in the past2. Mitochondria and chloroplasts contain DNA but lack     nucleus3. Mitochondria and chloroplasts contain their own     ribosomes4. Mitochondria and chloroplasts are able to self replicate by     binary fission5. Mitochondria and chloroplasts    move freely within the cell 

Primary and Secondary Endosymbiosis

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

Flagellated Protozoans• Single-celled organisms

o lack a cell wallo one or more flagellao pellicle layer of protein under

plasma membrane (shape)• Reproduce asexually - binary fission•  Different types of flagellated

protozoans:o Diplomonadso Parabasalidso Kinetoplastidso Euglenoidso Radiolarianso Foraminiferans

Giardia lamblia   

Alveolates• Characterized by membrane bound sacs (aveoli) under the

plasma membrane.o 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

Stramenopiles• Stramenopiles contains

o several groups of heterotrophs  o some groups of algae

• shared characteristic: flagellum- hairlike projections that help with motion and feeling

• most have both a hairy and smooth flagellumo always paired togethero 2 flagella=motile reproductive cells

Synura petersenii

Red Algae• red color derived from accessory pigment phycobili

o 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

o often alternation of generationso no flagellated life stage

Bonnemaisonia hamifera

Green Algae• aquatic autotrophs• chloroplasts similar to those of plants• contains two groups:

o 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

o charophyceans most closely related to land plants

Chlamydomonas nivalis

Amoebozoans• characterized by lobe-shaped pseudopodia• 3 types:

o Gymnamoebas heterotrophs

o Entamoebas parasites

o 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

 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