Chapter 28 ProtistsProtists are not a monophyletic group- Includes all eukaryotes that are not animals, plants or fungi- It contains many kingdoms- Most are unicellularo But also colonial and multicellular forms Multicellular- the cells are independent Colonial-cells are clones, they stick together, share resources, there is no specialization They evolved at several different timeso Some are multinucleate The nucleus divides without going through cytokinesis; there are many nuclei but only one cellOrigin of Eukaryotes- There was one common ancestor of all eukaryoteso Originated about 2.1 bya after the rise of oxygen levelso It was unicellularo Derived from archean-like prokaryoteso The origin hypothesis Devolvement of an infolded internal membranes (increases surface area for more metabolism) assisted in water control Growth in size Serial endosymbiosis (25.9)o See 28.2Protist DiversityFigure 28.3Excavata- All are unicellular with flagella- No cell wall- Diplomanadso Two haploid nucleio Anaerobic; reduced non-functional mitochondriao Ex- Giardia intestinalis-intestinal parasite- Parabasalidso Flagella and undulating membraneso Anaerobic, and reduced mitochondriao Ex- Trichomonas vaginalis- human vaginal parasite (STD)- Euglenozoanso Euglenids Autotroph with green chloroplasts Or heterotroph or mixotroph Ex-Euglena=free livingo Trypanosoma One large mitochondria Flagellum in undulation membrane Ex- Trypanosoma causes sleeping sicknessChromoalveolataAlveolates- All unicellular- All have “alveoli”- tiny cavities under the cell surface- Dinoflagellateso Heterotrophs or phytoplankton (algae) with extra red pigment in the chloroplastso Have a pair of flagella in perpendicular grooveso Have cell wall of many plates with internal cellulose plateso Some “blooms” cause fish kills “Red Tide”o Some are photosynthetic mutualists with coralso Some are bioluminescent- Apicomplexanso All are parasites of animals- no cell wallso Complex life cycles-multiple “forms”- more than one host in lifeo Apical complex helps them enter the hosto 1 end always penetrates the hosto Ex-Plasmodium Causes malaria, carried by mosquitoes KNOW malaria life cycle- Ciliateso Cilia for feeding and locomotiono Some are sessile and use the cilia to swirl water and bring food ino Cilia can bunch together and function almost like legso Animal like in function- no cell wallo With macronuclei and micronuclei (only used in reproduction)o Mostly use asexual reproductiono After about 700 cell divisions, it needs to go through sexual reproductiono KNOW life cycleStramenopiles- Diatoms are unicellular phytoplankton (algae) with extra yellow and brown pigmentso Silica walls that are glass-like, they look like petri disheso Some move by squirting liquid- Golden Algaeo Biflagellate phytoplankton with extra yellow and brown pigmentso Unicellular and colonialo Can coat themselves in glass beads- Brown Algaeo All are multicellular, mostly marine “seaweeds”o Photosynthetic with brown pigmentso Cell wall with align and celluloseo Ex Sargassum with floatso Ex- Kelp Humans eat it Align used as a commercial food thickener Has alternation of generations (28.16)- Oomyceteso Filamentous absorptive heterotrophs Superficial resemblance to fungio But they have cell walls with cellulose not chitino Ex- water moldo Don’t need to know life cycleo Ex- downy mildew- terrestrial plant parasiteo Ex Phytophthora- parasite that caused the potato famineRhizaria- Unicellular amoeboid heterotrophs feeding with threadlike pseudopodia- Radiolarianso Symmetric silica “skeletons”o Marine phytoplankton- Foraminifera (forams) (“pore bearing”)o Porous shells of calcium carbonateo Planktonic or sessile, mostly marineo Some are visible to the naked eyeo Important fossils in relative datingo 90% are extinctArchaeplastida- Chloroplasts come from primary endosymbiosis- Contain walls with cellulose- Red Algaeo Mostly marine, multicellular seaweedo Photosynthetic with unique red phycoerythrin accessory pigment Helps absorb light in deep watero Some filamentous, some with calcium carbonate that contribute to coral reef productiono NO flagellated cells in ANY stage of lifeo May not appear red when not at deptho Humans eat it (nori)o Cell walls are a source of  Carrageenan: used as a thickener (ice cream) Agar: petri dish culture- Chlorophytes (Green Algae)o Chloroplast structure and pigments are similar to plants They are key primary producerso Known as the green algae along with charophyteso They share a common ancestor with plantso Most are fresh water, many are marineo They have cellulose cell walls, many are bi-flagellatedo Unicellular forms Plankton ex- Chlamdomonas Mutualists ex- Hydrao Colonial forms- individual filaments Ex- spirogyra Ex- Volvoxo Multinucleate, large body formo Multicellular Freshwater algae ex-Cladophora Seaweed ex- Ulva (edible sea lettuce)Unikonta- Amoebozoanso Amoeboid heterotrophs with lobe like pseudopodiao No cell walls- Slime Moldso Moist terrestrial habitats (rotting wood)o Eat by phagocytosiso Produce stalked, sport producing “fruiting” bodies when conditions are harsho Plasmodial slime molds feed as a multinucleate diploid plasmodium (28.24)o Cellular slime molds feed as single cells They aggregate when food is scarce (28.25)- Gymnamoebaso Free-living heterotrophic, feeding on bacterial protists and detrituso They are both aquatic and terrestrialo No cell wallo Ex- Amoeba proteus (28.3)- Entamoebaso Parasitic on vertebrates and some insectso Durable cyst formo Ex- Entamoeba histolytica- amoebic