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FUNGUS-LIKE PROTISTS. Phylum Myxomycota Phylum Acrasiomycota Phylum Oomycota. http://www.nytimes.com/2011/10/04/science/04slime.html?_r=5&pagewanted=all&. CHARACTERISTICS. why fungus-like? appearance mode of nutrition with centrioles no chitin in cell walls non-photosynthetic
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FUNGUS-LIKE PROTISTS Phylum Myxomycota Phylum Acrasiomycota Phylum Oomycota http://www.nytimes.com/2011/10/04/science/04slime.html?_r=5&pagewanted=all&
CHARACTERISTICS • why fungus-like? • appearance • mode of nutrition • with centrioles • no chitin in cell walls • non-photosynthetic • 2-stage life cycle • spore-bearing mold-like stage • free-living amoeba-like stage Stemonitis fusca Comatrichatyphoides http://tywkiwdbi.blogspot.com/2011/11/slime-mold.html, http://www.nationalgeographicstock.com/comp/04/442/1030283.jpg
Dominant state near rich sources of food (phagocytic) Fruiting body Spore-bearing structure Cells aggregate into a slimy mass when food is scarce and moves to a better location http://www.nsf.gov/od/lpa/news/03/pr03106_images.htm
SLIME MOLDS • Phylum Myxomycota Acellular slime molds • Phylum Acrasiomycota Cellular slime molds
Phylum MyxomycotaAcellular or plasmodial slime molds • plasmodium • large cytoplasmic mass (multinucleate) • feeding stage • unfavorable conditions: “fruiting” • sporangia spring up from plasmodium • meiosis haploid spores flagellated gametes →diploid zygote (sexual reproduction) →*diploid amoeboid cells • e.g. Physarum http://biodidac.bio.uottawa.ca
http://home.sandiego.edu/~gmorse/2009BIOL221/Study_guide2/plasmodial.jpghttp://home.sandiego.edu/~gmorse/2009BIOL221/Study_guide2/plasmodial.jpg
http://xkcd.com/877/ , http://www.uknature.co.uk/F.septica.jpg, http://i55.tinypic.com/313k32b.jpg, http://i56.tinypic.com/flly6t.jpg
Phylum Acrasiomycotacellular slime molds • pseudoplasmodium • separated by cell membranes • cell aggregation • slug-like form • migrates to form fruiting body • spores by mitosis • e.g. Dictyostelium discoideum
Phylum Oomycotawater molds/downy mildew • cellulosic cell wall • live on organic matter in water, plant parasites on land • hyphae finely-branched single-celled filaments • coenocytic/aseptate no walls between cells • motile spores Phytophthora infestans http://www.bluepointenvironmental.com/wp-content/uploads/2012/01/coenocytic-hyphae-60x-LP.jpg
Significance • decomposers • food source of other organisms • parasites of plants (grapes, tomatoes, potatoes) and animals • used to plan routes (shortest distance) • rich areas for biological study http://www.gardencentre.ie/blog/wp-content/uploads/2012/05/potato-blight.jpg, http://media.treehugger.com/assets/images/2011/10/tokyo-mold-railway.jpg