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Contractile vacuole action. Amoeboid movement. See it!. Chapter 31 ~ Fungi. Humongous Fungus Honey Mushroom Blankets Forest, Kills Trees.
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Humongous Fungus Honey Mushroom Blankets Forest, Kills Trees It is as large as 1,665 football fields combined. It is 3.4 square miles in size and covers 2,200 acres of land in the Blue Mountains of eastern Oregon.
Cell wall Cell wall Nuclei Pore Septum Nuclei Septate hypha Coenocytic hypha Fungi • Heterotrophic by absorption (exoenzymes) • Decomposers (saprobes), parasites, mutualistic symbionts (lichens) • Hyphae: body filaments •septate (cross walls) •coenocytic (no cross walls) • Mycelium: network of hyphae • Chitin cell walls (polysaccharide)
Reproductive structure Hyphae LE 31-2 Spore-producing structures 20 µm Mycelium
Fungus Life Cycle • Most have 3 distinct phases: • Haploid (n) • Heterokaryotic (n + n) (think of Sordaria) • Diploid (2n) Asexual phases: (n spores, n clones)Sexual Phases: (n spores, w/ genetic variety) Plasmogamy (cytoplamic fusion) Dikaryotic (n + n) Karyogamy (nuclei fusion) Diploid (2n) Meiosis (spores n) Bread Mold Life cycle
Key Heterokaryotic stage Haploid (n) Heterokaryotic (n + n)) PLASMOGAMY (fusion of cytoplasm) Diploid (2n) KARYOGAMY (fusion of nuclei) Spore-producing structures Zygote SEXUAL REPRODUCTION Spores ASEXUAL REPRODUCTION Mycelium MEIOSIS GERMINATION GERMINATION Spore-producing structures Spores
Fungi Diversity, I • Phy: Chytridiomycota •aquatic fungi; chytrids •lineage closest to protists (flagella) • Phy: Zygomycota •Rhizopus (food mold) •mycorrhizae: mutualistic with plant roots •zygosporangia: resistant structure (freezing and drying)
Fungi Diversity, II • Phy.: Ascomycota •sac fungi • yeasts, truffles, morels, Sordaria •asci: sexual spores •conidia: asexual spores • Phy.: Basidiomycota • club fungus •mushrooms, puffballs, shelf fungus, rusts •basidiocarps: produce sexual spores
Specialized Lifestyles, I • Molds •only the asexual stage (asexual spores) •Penicillium (antibiotic, cheese) • Yeasts •unicellular, asexual budding •Saccharomyces (bread, alcohol)
Specialized Lifestyles, II • Lichens • symbiotic association held in a hyphae mesh •alga provides food, fungus provides physical environment •pioneer organisms •air pollution detection • Mycorrhizae •root and fungi mutualism •found in 95% of vascular plants •exchange of organic minerals •increases absorptive surface of roots