The Protists - West Chester...
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1/15/15 1 The Protists Plantae – chlorophyll a and b, conifers, mosses, ferns, flowering plants Eubacteria- unicellular, range of environments Archae – unicellular, extreme habitats Protista – multicellular defined by absence of characteristics Fungi – ecological significance, mycorrhizae Animalia – animals, metazoa
Transcript of The Protists - West Chester...
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The Protists!
Plantae – chlorophyll a and b, conifers, mosses, ferns, flowering plants !
Eubacteria- unicellular, range of environments!Archae – unicellular, extreme habitats!
Protista – multicellular defined by absence of characteristics!
Fungi – ecological significance, mycorrhizae!
Animalia – animals, metazoa !
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Emergence of the !Eukaryotes!!Proposes that certain prokaryotes were incorporated into a larger species of prokaryote = prey or parasites!!Chloroplasts = photosynthesizing cyanobacteria!!Mitochondria = aerobic heterotrophs!!!!Host and endosymbiont became interdependent to form a single organism!
The Protists!- Many single celled members of the kingdom Protista!
- Clearly eukaryotes = distinct nuclei, membrane bound organelles!
- Remarkably diverse in terms of size, morphology, nutrition, locomotion and reproduction!
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Protists can be – !unicellular, colonial, multicellular!
Volvox!
Paramecium!
Euglena!
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General Protozoan Characteristics!Entire organism is enclosed in the cell membrane = naked or armored, different composition!!Cytoplasms = clear outer ectoplasm and less transparent, fluid region or endoplasm!!Organelles typical of most multicellular metazoan cells !!Many protozoan protists contain organelles not found among metazoa, e.g. contractile vacuoles, trichocysts!
Locomotory Appendages!Cilia – microtubular construction, coordinated!ciliary beat, generally many = brush border !https://www.youtube.com/watch?v=RakqKYHenxU!!Flagella – same construction, but different number and size (length), different pattern of movement!https://www.youtube.com/watch?v=jl0TzaWUQWk!!Podia – extensions of the cytoplasm created by cytoplasmic streaming!!!!
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PLANKTON!
Euglenida:!Euglena, Phacus, Trachelomonas!
aqueous environment = marine or freshwater, free!!flagellar movement typically of the members of the phylum formerly known as Sarcomastigophora!!very mobile (examine live specimens in lab) = due to a pellicle rather than cell wall!!mixotrophic = poor environmental conditions may result in change from autotrophic to heterotrophic and vice versa!!eyespot = positively phototactic = when mobile and autotrophic you need to be able to move actively towards light!
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Flagellae = often referred to as single!
Reproduction = asexual!absorption of flagellum!formation of microtubules!= below pellicle!mitosis!= creation of immature zoospores!zoospores break apart, grow!
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Kinetoplastida:!Trypanosoma, Leishmania, Rhyncomonas!
also formerly belonging into Sarcomastigophora!symbiotic and includes pathogenic parasites = African sleeping sickness!affect different vertebrates, !including humans!!!!!!!flagellum attached to mitochondrion (kinetoplast) via undulating membrane = energy support for movement!transmitted through bite of Tsetse fly!Asexual = binary fission, sexual = nuclear fusion!
Ciliophora:!Paramecium, Didinium, Tetrahymena!
probably the most complex of unicellular organisms!!!diverse protist group, is named for their use of cilia!!Macro & micronucleus, vacuoles (digestive, contractile), cytostome vs cytoproct, extrusosomes!!Mostly freshwater, few parasites (1 causing human disease)!
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Feed on algae or other ciliates!
Reproduction != asexual by division!= sexual by conjugation, cytoplasmic !bridge, macronuclei disintegrate, micronuclei exchange, formation of new macronuclei!
Cyst formation = dry periods!
Dinoflagellata !Dinophyta, Pyrrophyta (Gr. dinos: whirling; L. flagellum: whip) (= Pyrrophyta) (Gr. pyros: fire, and phyton: plant) !– refers to bioluminescence of many forms!- most are biflagellated, unicellular!- may be unarmored (naked) or armored (thecate, pellicle) ! !!
Dinophysis!
Peridinium!
Ceratium!
Noctiluca! Gymnodium)
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Rhizopoda!Amoeba, Entamoeba, (Chaos)!
aqueous = freshwater and marine, well watered soils!!mostly free-living heterotrophs !!pseudopodia = extensions!!parasites = Entamoeba histolytica = amoeboid dysentery!!reproduction by binary fission!
marine, siliceous skeleton!= bubbly appearance!!related to what used to be Zoomastigophora!!axopodia = very thin spicule like cytoplasmic extensions, generally not involved in locomotion!!reproduction = asexual, binary fission!
Actinopoda!Actinosphaerium, Radiolarians!
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Parabasilida:!Trichonympha, Trichomonas!
generally symbiotic in higher organisms!= help them digest cellulose!!flagellated = between 4-thousands!!anaerobic = lack mitochondria!!
