The Protists Eukaryotes. Most unicellular. Most aerobic. Moist environments Can be photoheterotrophs or photoautotrophs, chemoheterotrophs or mixotrophs. Flagella or cilia. All protists can reproduce asexually, some sexually Plankton.

Endosymbiosis Eukaryotic cells evolved from symbiotic combinations of prokaryotic cells. Mitochondria  aerobic heterotrophic prokaryotic cells Chloroplasts  photosynthetic prokaryotes that became endosymbionts within larger cells.

Evidence for Endosymbiosis Similarities between modern bacteria and the chloroplasts/mitochondria of eukaryotes: *size *membrane enzymes and transport systems *circular DNA molecules *process of division *ribosomes (and rRNA sequence) similar

The Candidate Kingdoms Archaezoa Euglenozoa Alveolata Stramenopila Rhodophyta Green Algae

Candidate Kingdom Archaezoa Giardia have two nuclei, flagella, and no mitochondria or plasmids (…parasites)

Candidate Kingdom Euglenozoa Autotrophic and/or heterotrophic flagellates Euglena 1 or 2 flagella Kinetoplasts parasitic, e.g. causes African Sleeping Sickness (bite of tsetse fly) Trypanosoma

Candidate Kingdom Alveolata Dinoflagellates, phytoplankton, cause red tides. Brownish red color from xanthophyll. Apicomplexans, plasmodium, causes malaria. Ciliates, paramecium, freshwater. Next Group

Dinoflagellates http://www.microscopy-uk.org.uk/mag/artsep01/dinof.html http://www.microscopy-uk.org.uk/mag/indexmag.html

Apicomplexans Leishmania Parasite infected erythrocyte

Life history of Plasmodium

Ciliates Stentor Paramecium Vorticella

Pseudopod “Protists” Taxonomic lineage unclear, so no clear kingdom found Rhizopods, amoebas Actinopods, radiolarians and heliozoans (delicate silica shells). Foraminiferans, marine with porous calcereous shells. Used as index fossils. Slime Molds, cytoplasmic streaming

Rhizopod Amoeba

Actinopods Radiolarians

Foraminiferans

Slime Molds Plasmodial Slime Mold – Myxomycota. Heterotrophic,brightly colored, multinucleated ameboid mass.

Candidate Kingdom Stramenopila Diatoms (bacillariophyta)– unicellular plankton with box-like silica walls. Diatomaceous earth. Golden Algae (chrysophyta) – yellow and brown carotene and xanthrophyll pigments Brown Algae (phaeophyta)- largests and most complex. Seaweeds and kelps, may be as long as 60m. Water Molds (oomycota) – white rusts and downy mildews Next Group

Diatoms                                                          

Golden Algae - Chrysophyta

Brown Algae - Phaeophyta Kelp Harvesting

Kelp Structures Analogous plant-like structures Body = thallus Root-like structure – holdfast Stem-like structure – stipe Leaf-like structure - blades

Water molds, white rusts and downy mildews White rust on spinach

Candidate Kingdom Rhodophyta Lack flagella Red color from the pigment Marine Multicellular

Candidate Kingdom Green Algae *Many scientists advocate inclusion of green algae into the plant kingdom. *More than 7000 species, mostly freshwater. *Unicellular – Chlamydomonas *Colonial – Volvox *Multicellular – Ulva Ulva

Green Algae - Chlorophyta Volvox Chlamydomonas Spirogyra

Chlamydomonas Life Cycle

Ulva Life Cycle