440 likes | 829 Views
Fungi. Chapter 31. Plantae Fungi Animalia Protista. Monera. Kingdom Fungi. About 100,000 species. Uses: medicine food Ecological value: major decomposers symbiotic relationships (N 2 fixers) Problems: some strains are deadly athletes foot destroy library books
E N D
Fungi Chapter 31
Plantae Fungi Animalia • Protista Monera
Kingdom Fungi About 100,000 species • Uses: • medicine • food • Ecological value: • major decomposers • symbiotic relationships (N2 fixers) • Problems: • some strains are deadly • athletes foot • destroy library books • destroy crops
Some fungi are pathogens • About 30% of the 100,000 known species of fungi are parasites, mostly on or in plants. • American elms: Dutch Elm Disease • American chestnut: • chestnut blight Was once one of America's most dominant trees
Some fungi are pathogens • Other fungi, such as rusts and ergots, infect grain crops, causing tremendous economic losses each year.
Some fungi are pathogens • Curse of the Mummy
Some fungi are persistant Athletes Foot
Kingdom Fungi Eukaryotic, absorptive Mostly multicellular (except few, e.g. yeast) Heterotrophic (decomposers & parasitic) Mycelium (body of hyphae)
Kingdom Fungi • Firm cell walls (generally of “chitin”) • “Spores” as reproductive bodies • Unique chromosomes and nuclei • Includes molds, yeasts, rusts, and mushrooms
hyphae - the vegetative bodies of most fungi, constructed of tiny filaments • mycelium -an interwoven mat of hyphae
Human hair Fungal hypha
Septate hypha: • multicellular • walls divided by septa • Ceonocytic hypha: • continuous cytoplasm mass • multinucleate • no septa
Haustoria: • Modified hyphae found in parasitic fungi • Function: absorb nutrients from host • Some fungi even have hyphae adapted for preying on animals.
Kingdom Fungi Division Chytridiomycota Division Ascomycota Division Basidiomycota Division Zygomycota Division Deuteromycota
? Deuteromycota Fungus-like protist
The four fungal phyla can be distinguished by their reproductive features.
Division Chytridiomycota • mainly aquatic. • Some are saprobes, while others parasitize protists, plants, and animals. • chitinous cell wall • flagellated zoospores • the most primitive fungi
Division Zygomycota “Zygote fungi”(bread molds) Zygote = “mated” hyphal strands Live in soil, water Some are parasites 600 species
The zygosporangia are resistant to freezing and drying. • When conditions improve, the zygosporangia release haploid spores that colonize new substrates. • Pilobolus aiming its spores.
The zygomycete Rhizopus can reproduce either asexually or sexually.
Division Ascomycota “Sac fungi”(truffles, yeast) Beer > 6,000 years Wine > 8,000 years Lichens Decomposers, pathogens “yeast” describes a form of fungi (i.e., non-hyphal) 60,000 species
Division Ascomycota Scarlet cup Morchella truffles
Division Ascomycota Close up of cheese showing blue-green mycelium of Penicillium roqueforti. Roquefort cheese
Ascomycetes are characterized by an extensive heterokaryotic stage during the formation of ascocarps.
Division Basidiomycota “Club fungi”(mushrooms) Club-shaped reproductive structure Food Plant diseases 25,000 species
The life cycle of a club fungus usually includes a long-lived dikaryotic mycelium.
Division Deuteromycota • “Imperfect fungi”(penicillin) • Unrelated group • Asexual • No info on sexual cycle 25,000 species
Penicillin Woops… now Ascomycota
Candida albicans “yeast infection”
Plant-Fungal Relationships Mycorrhizae (“fungus roots”) 90% of tree species have this association Very important to absorption of water and nutrients
Soil surface Plant roots Mycorrhizae Increases s.a. for absorption