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Protista: modes of nutrition

· Rhodophyta: phtotosynthetic autotrophy

greg_farley, tigger

www.campbellbiology.com

Protista: modes of nutrition

· Amoebozoa: heterotrophy

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Heterotrophic Protista

· Amoeboids Feeding is via

phagocytosis (for solids) or pinocytosis (for liquids):

pseudopodia extend around a prey item and encapsulate it into a vacuole.

Protista: modes of nutrition

· Euglenozoa ­ mixotrophy

(a.k.a. facultative heterotrophy) Can photosynthesize, but also absorb nutrients directly from the environment.

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· 10 groups:

­ ­ ­ ­ ­ ­ ­ ­ ­ ­

"Kingdom" Protista

Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Rhodophyta Chlorophyta

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· 10 groups:

­ ­ ­ ­ ­ ­ ­ ­ ­ ­

"Kingdom" Protista

Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Rhodophyta Chlorophyta

Diplomonadida and Parabasala

Primary synapomorphies: · lack of plastids · modified mitochondria: no mtDNA, no electron transport, no citric acid cycle · mostly anaerobic

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Diplomonadida

Principal characteristics: · two equal-sized nuclei · multiple flagellae

Eukaryotic flagellae: 9+2 structure

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Parabasala

Also called Trichomonadida Primary characteristic: · undulating membrane

· 10 groups:

­ ­ ­ ­ ­ ­ ­ ­ ­ ­

"Kingdom" Protista

Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Rhodophyta Chlorophyta

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Primary synapomorphy: crystalline structure inside flagellae (function unknown) Diverse modes of nutrition: predation photosynthesis parasitism 2 groups (?) Kinetoplastids Euglenids

Euglenozoa

Euglenozoa: Kinetoplastids

Primary synapomorphy: single large mitochondrion with its own organized DNA (called a kinetoplast) No general statements about feeding Many diseases:

· Sleeping sickness · Chagas' disease Labile surface proteins are used to evade host immune systems a.k.a. trypanosomes

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Euglenozoa: Euglenids

Primary synapomorphies:

· 1-2 flagellae emerge from a pocket at one end of the cell · Store glucose as paramylon (polymer) · Pellicle (proteinaceous) beneath plasma membrane Many are facultative heterotrophs

· 10 groups:

­ ­ ­ ­ ­ ­ ­ ­ ­ ­

"Kingdom" Protista

Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Rhodophyta Chlorophyta

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Alveolata

Primary synapomorphy: have sacs (function unknown) beneath the plasma membrane. Much molecular support for this clade, as well. 3 primary groups:

· Dinoflagellates · Apicomplexans · Ciliates

Dinoflagellates

Primary synapomorphy: pair of flagellae, each in a groove on the outside of the cell. Flagellae are usually perpendicular. Largely autotrophic, all planktonic

· Some with cellulose armor `plates' · Some heterotrophs · Some colonial forms Responsible for "red tide" events; can be toxic Many are symbiotic inside corals (zooxanthellae) Many are bioluminescent

Pfisteria shumwayae

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All are obligate parasites; clade name refers to the structure at the `anterior' end, the apical complex

Apicomplexa (= Sporozoa)

Also possess an apicoplast (a nonphotosynthetic plastid) As parasites, most have complex life cycles

Life cycle of Plasmodium vivax , the malaria parasite

Cells covered in cilia. Movement is coordinated among cilia (how?) Different types of cilia include: Oral or somatic In rows: kineties Cylindrical groups: cirri ­ Have at least one macronucleus (somatic, >1n; sometimes "dozens of copies" of genome in each) and at least one micronucleus (reproductive, n)

Ciliates

www.nonlocal.com/ hbar/paramecium.html

http://www.microscopies.com/DOSSIERS/Magazine/Articles/WD-STENTORS/Famille%20Stentoridae.html

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· 10 groups:

­ ­ ­ ­ ­ ­ ­ ­ ­ ­

"Kingdom" Protista

Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Rhodophyta Chlorophyta

Stramenopiles

Four major groups:

· · · · Oomycetes (water molds) Diatoms (Bacillariophytes) Chrysophyta (golden algae) Phaeophyta (brown algae)

Single snyapomorphy: flagellae have hairlike projections. In most, a `hairy' flagellum is paired with a `smooth' flagellum.

Synura petersenii

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Oomycetes

Water molds, downy/powdery mildews, white rusts Originally thought to be fungi: have filaments (hyphae) like fungi do. However:

· · · oomycetes have flagellae; fungi do not oomycete cell walls are cellulose (fungi are chitin). oomycetes are predominantly diploid (fungi: n)

http://www.bio.uu.nl/~molgen/research.html

Diatoms

Unicellular photoautotrophs with an SiO2 shell ~100,000 living species; all planktonic store sugars as laminarin (like brown and golden algae); also store lipids

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Chrysophyta (golden algae)

Mostly unicellular photoautotrophs cells are usually biflagellate largely planktonic occasionally mixotrophic some colonial forms Still a `mixed bag' of organisms?

Phaeophyta (brown algae)

Mostly multicellular photoautotrophs: kelps/etc.

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· 10 groups:

­ ­ ­ ­ ­ ­ ­ ­ ­ ­

"Kingdom" Protista

Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Rhodophyta Chlorophyta

Cercozoa

Organisms with threadlike pseudopodia 2 groups:

· Foraminiferans: Have pseudopodia and tests made of CaCO3 · Chlorarachniophytes

3rd group: not Cercozoa, but closely related

· Radiolarians: similar to forams, but with Si tests

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Chlorarachniophytes

Organisms with threadlike pseudopodia and acquired algal photosymbionts

http://myweb.dal.ca/jmarchib/chlorarachniophytes.html

Cercozoa

Foraminifera: test is CaCO3

tests make up the White Cliffs of Dover and the limestone in the Great Pyramids

Radiolaria: test is Si or SrSO4

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"Kingdom" Protista

· 10 groups:

­ ­ ­ ­ ­ ­ ­ ­ ­ ­ Diplomonadida Parabasala Euglenozoa Alveolata Stramenopila Cercozoa Radiolaria Amoebozoa Rhodophyta Chlorophyta

Amoebozoa

Organisms with lobe-shaped pseudopodia 3 groups:

· Entamoebas: parasites · Gymnamoebas · Slime Molds

http://www.btinternet.com/~stephen.durr/amoebaproteus.html

http://webnt.calhoun.edu/distance/internet/Natural/bio220-collier/entamoeba_trophozoite.jpg

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Amoebozoa: slime molds

· Plasmodial slime molds (Myxomycota)

­ Plasmodium: diploid, multinucleated, cytoplasmic mass ­Feeds by

phagocytosis, usually on dead organic matter ­Cytoplasm circulates within the plasmodium ­Mitosis without cytokinesis yields many nuclei

http://www.merian.fr.bw.schule.de/beck/skripten/bilder/Pilzplas.jpg

Amoebozoa: slime molds

Cellular slime molds (Acrasiomycota)

­ individual ameboid cells; turn into "pseudoplasmodium" when stressed ­ no flagellated stages

http://upload.wikimedia.org/wikipedia/en/8/8b/Slime_mold.jpg

http://dictybase.org/

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Rhodophyta

Red algae: 6,000+ spp; get color from accessory pigment called phycoerythrin · also has chlorophyll · most abundant algae in shallow waters

Chlorophyta

Green algae: color from chlorophyll chloroplasts very much like Plantae 2 main groups: Chlorophytes (7,000+ spp.) Charophyceans

www.msc.ucla.edu/.../Plants/ Chlorophyta/Codium.jpg

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Green Algae: Charophycaea

· Most likely ancestor for Kingdom Plantae

clade.acnatsci.org/ mccourt/

http://bib18.ulb.ac.be/Botanique_I/image/390158992005_Volvox.jpg

Chlorophytes

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Green Algae: Charophycaea

· Four synapomorphies that tie Plantae to charophycean algae:

· Cellulose is made by rosette complexes: proteins in the cell membrane generate cellulose fibrils · Peroxisomes in association with chloroplasts · Sperm ultrastructure · Mitotic cell plate involves a phragmoplast: aligned cytoskeletal elements and Golgiderived vesicles

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Nifty Protist Weblinks

· http://biology.unm.edu/ccouncil/Biology_203/ Summaries/Protists.htm · http://tolweb.org/tree/

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