Chapter 28 Friday February 26 2016 2 31 PM Chapter 28 Protists Overview of Eukaryotes Anton von Leuwenhoek 1675 Eukaryotic Cells o Size o Makes them eukaryotic nucleus internal membranes mitochondria plant animal plants have chloroplasts microtubules cilia cell division Origin Hypotheses o Single ancestor of all eukaryotes 1 A heterotrophic archaean gained nucleus and ER from infolded plasma membrane Formation of internal membranes by infolding the plasma membrane you can isolate DNA into a nucleus 2 Gained mitochondrion from endosymbiosis of aerobic heterotrophic bacterium Beneficial mutualist chugging out Origin of mitochondrion o Ancestor of all photosynthetic eukaryotes 1 Eukaryote with mitochondrion gained chloroplast from endosymbiosis of cyanobacterium o Secondary 2 o degree endosymbiosis 1 Eukaryotes engulfed eukaryotic alga cells eukaryote with chloroplast which became unique plastids in several protist lines Eukaryotic Organization o Unicellular Entire life cycle as single cell Diversity of organelles diverse forms o Colonial Daughter cells remain connected together through mitosis Share resources Some specialized but changeable roles o Multicellular Cell specialization interdependence Cell junctions hold together Cell communication and coordination o Multinucleate Nuclear division without cytokinesis Allows the flow of material to go through much faster Eukaryotic Diversity o Familiar multicellular kingdoms Plants animals fungi o Protists All other eukaryotes Most are aquatic or live in moist tissues parasites plants Excavata o Diplomonads Unicellular flagella no cell wall applies to all repeated for the rest Anaerobic reduced mitochondria Most are parasitic Ex Giardia intestinalis intestinal parasite Durable cysts consumed in water o Parabasalids Unicellular flagella no cell wall Anaerobic reduced mitochondria Most are symbiotic Ex Trichomonas vaginalis human vaginal parasite STD o Euglenozoans Unicellular no cell wall flagella with crystalline rod Ex Euglena free living Autotroph with green chloroplasts 2 o Have a contractile vacuole get rid of water with vacuole Chloroplast photoautotroph Pellicle OR heterotroph OR mixotroph switches nutrition Ex Trypanosoma blood parasite Causes sleeping sickness carried by tse tse fly Stramenophiles o Diatoms Unicellular phytoplankton algae Key primary producers marine ecosystem With yellow and brown accessory pigments Silica walls glass like like a petri dish diatomaceous earth deposits No flagellum except in gamete o Brown Algae Multicellular mostly marine seaweeds Major 1 o primary producers With brownish accessory pigments Large thallose form Thallus the stalk Blade Stripe Holdfast Cell wall with cellulose and algin Ex Sargassum has floats Ex kelp Laminaria and other species Humans eat it Algin used as commercial food thickener Kelp has alternation of generations same as ferns There is a haploid and diploid multicellular form Sporophyte makes spores haploid dispersal units goes through meiosis Occurs in special organs called sporangia spore producing area Spores grow into multicellular gametophytes separate sexes Gametophytes produces gametes Male female produces and get fertilization fused gametes Zygote formed diploid Grows into sporophyte Alveolates o Dinoflagellates Unicellular aquatic heterotrophs or phytoplankton with reddish acc Pigments Pair of flagella in perpendicular grooves Many with internal cellulose plates technically no cell walls Some blooms cause fish kills and red tide Many photosynthetic mutualists with corals Some are bioluminescent o Apicomplexans Unicellular parasites of animals no cell wall Apical complex helps them enter host cells Complex life cycles Requires more than one host Multiple forms Ex Plasmodium Causes malaria carried by mosquitos o Ciliates Unicellular ingestive heterotrophs with no cell wall freshwater and marine Cilia for feeding and locomotion Animal like in function With macronucleus controls cell function and micronucleus for genetic recombination Ex Paramecium Most reproduction is asexual division Conjugation trades haploid mocriinuclei Meiosis and recombination without gametes Unique to ciliates Rhizaria o Radiolarians Unicellular marine plankton Feed with threadlike psudopodia Symmetric siilica skeletons o Foraminiferans forams Unicellular mostly marine plankton Feed with threadlike pseudopodia Porous shells tests of calcium carbonate Some size visible to eye Important fossils for relative dating Archaeplastida o Archae old o Plastida plastids Chloroplasts from primary endosymbiotic event With cell walls include cellulose o Archaeplastida Red Algae Mostly marine multicellular seaweeds Unique chloroplasts include red phycoerythrin accessory pigment Helps absorb Some thallose some filamentous some make CACO2 Humans eat it Uniue cell wall polysaccharides Carrageenan thikener ce cream Agar for petri dish cultures food Chlorophytes Aka green algae along with Charophytes Chloroplasts same as in plants Most are freshwater many marine Many with bi flagellated cells Unicellular forms Phytoplankton Ex Chlamydomonas Mutualists Multicellular forms Freshwater algae Ex Chladophora Seaweeds Ex Ulva edible sea lettuce Amoebozoans Slime Molds o Live in most terrestrial habitats rotting wood etc o Use pseudopodia to move and ingest bacteria Intercellular digestion o Produce stalked spore producing fruiting bodies when conditions are harsh o Plasmodial smile molds feed as a multinucleate plasmodium o Ceullular slime molds feed as single cells Then gather as an aggregate when food is gone to form spores Produce a spore producing body where spores disperse Tubulinids replaces Gymnamoebas o Unicellular free living o Aquatic or moist terrestrial o Moves with pseudopodia feeding on bacteria protists detritus o Ex Amoeba proteus Entamoebas Enta inside internal o Unicellular parasites of animals o Kills and feeds on host cells o Spreads by durable cyst form o Ex Entamoeba histolytica causes amebic dysentery Pseudopodia actin filaments sliding along periphery of the plasma membrane