Chapter 28Friday, February 26, 20162:31 PM Chapter 28 - Protists Overview of Eukaryotes-Anton von Leuwenhoek, 1675-Eukaryotic CellsoSizeoMakes them eukaryotic - nucleus, internal membranes, mitochondria (plant/animal), plants have chloroplasts, microtubules (cilia, cell division)-Origin HypothesesoSingle ancestor of all eukaryotes1. 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 nucleus2. Gained mitochondrion from endosymbiosis of aerobic heterotrophic bacteriumBeneficial mutualist, chugging outOrigin of mitochondrionoAncestor of all photosynthetic eukaryotes1. Eukaryote (with mitochondrion) gained chloroplast from endosymbiosis of cyanobacteriumoSecondary (2^o degree) endosymbiosis1. Eukaryotes engulfed eukaryotic alga cells* (*eukaryote with chloroplast) which became unique plastids in several protist lines-Eukaryotic OrganizationoUnicellular-Entire life cycle as single cell-Diversity of organelles => diverse formsoColonial-Daughter cells remain connected together (through mitosis)-Share resources-Some specialized, but changeable rolesoMulticellular-Cell specialization, interdependence-Cell junctions - hold together-Cell communication and coordinationoMultinucleate-Nuclear division without cytokinesisAllows the flow of material to go through much faster-Eukaryotic DiversityoFamiliar multicellular kingdoms:-Plants, animals, fungio"Protists"-All other eukaryotes-Most are aquatic or live in moist tissues (parasites/plants)-ExcavataoDiplomonads-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 wateroParabasalids-Unicellular; flagella; no cell wall-Anaerobic; reduced mitochondria-Most are symbiotic-Ex. Trichomonas vaginalis - human vaginal parasite (STD)oEuglenozoans-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)-StramenophilesoDiatoms-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 gameteoBrown 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-AlveolatesoDinoflagellates-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 bioluminescentoApicomplexans-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 mosquitosoCiliates-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-RhizariaoRadiolarians-Unicellular marine plankton-Feed with threadlike psudopodia-Symmetric siilica "skeletons"oForaminiferans ("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-ArchaeplastidaoArchae - oldoPlastida - plastids-Chloroplasts from primary endosymbiotic event-With cell walls include celluloseoArchaeplastida-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 MoldsoLive in most terrestrial habitats (rotting wood, etc.)oUse pseudopodia to move and ingest bacteria-Intercellular digestionoProduce stalked, spore-producing "fruiting" bodies when conditions are harshoPlasmodial smile molds feed as a multinucleate plasmodiumoCeullular 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)oUnicellular, free-livingoAquatic or moist terrestrialoMoves with pseudopodia feeding on bacteria, protists, detritusoEx. Amoeba proteus-Entamoebas (Enta - inside/internal)oUnicellular parasites of animalsoKills and feeds on host cellsoSpreads by durable cyst formoEx. Entamoeba histolytica - causes amebic dysentery-Pseudopodia - actin filaments, sliding along periphery of the plasma