Fungi

Characteristics Multicellular (few exceptions like yeast) Eukaryotic Heterotrophic, break down food then absorb, saprotrophic Some are parasitic, cause disease Economically important, food, fermentation, medicines Mutualistic relationships

Structure of Fungi Mycelium – make up body of most fungi Hyphae – network of fibers that make up mycelium, increase surface area for fungi  Some have septa – cross walls, have pores  Non-septate fungi, multinucleated Cells contain chitin in cell wall, lack chloroplasts Non motile, not flagella, grow toward food source

Reproduction Sexual  haploid hyphae  dikarytoic  diploid zygote  Hyphae from 2 different fungi meet and fuse  Produce windblown spores to insure dispersal Spore – reproductive cell that develops into a new organism without the need to fuse with another reproductive cell.

Reproduction Asexual  Production of spores by specialized part of single mycelium.  Fragmentation and budding (yeast) can occur

Fungi Evolution 570 mya Maybe evolved from red algae (both lack flagella) Thought to be part of Plantae and Protista kingdoms Fungal groups are classified according to differences in life cycle and type of structure that produces spores.

Phyla Zygomycota Saprotrophic, in soil and food, some parasitic Black bread mold – Rhizopus stolonifer  Stolon are horizontal hyphae on surface of bread  Rhizoids grow into bread, anchor the mycelium and carry out digestion.  Sporangium – produces spores called sporangiospores Zygospore – seen in sexual repro.  Forms prior to meiosis and production of spores  23.3 page 401

Phylum Ascomycota Sac fungi  Sexual ascomycetes (yeasts, red bread molds, mildews, morels, truffles, chestnut blight, ergot)  Asexual ascomycetes, no sexual repro. observed, (Aspergillus, Candida and Penicillium molds) Penicillium has been renamed Talaromyces  Essential to digesting not easily decomposed materials such as cellulose, jet fuel)

Sac Fungi Symbiotic  lichens (with algae),  plant roots (mycorrhizae) Reproduction – conidiospores (spores) Ascus – fingerlike sac that develops during sexual reproduction  Fruiting body – reproductive structure where spores are produced and release.

Economical benefits/ non-benefits Food – beer, wine, cheese, coke Medical – antibiotics, steroids, cyclosporin Disease – ringworm, rose gardener’s disease, Chicago’s disease… Yeasts – Candida - infections Molds – Aspergillus – soy sauce, pathogenic to humans, carcinogen

Basidiomycota Club fungi – mushrooms, toadstools, puffballs  Food, disease (smuts and rusts) Reproduction – usually sexually  Basidium – club shaped structure in which spores develop

Symbiotic relationships Lichens – fungus and green algae or cyanobacteria.  Thought of as mutualistic but may be parasitic, algae do not benefit  3 types, environmental indicators, live in extreme conditions Mycorrhizae – soil fungi and roots of most plants  Plants more successful in poor soils  Helps plants acquire mineral nutrients