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Fungus – Mycology-BIOLOGY 11. Characteristics. Eukaryotic Unicellular, colonial, or multicellular Heterotrophic Must live in contact with their food which is often decaying Cell walls made of Chitin (not cellulose as found in green plants) May contain centrioles. Figure 26.21c. Eukarya.
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Characteristics • Eukaryotic • Unicellular, colonial, or multicellular • Heterotrophic • Must live in contact with their food which is often decaying • Cell walls made of Chitin (not cellulose as found in green plants) • May contain centrioles
Figure 26.21c Eukarya Land plants Dinoflagellates Forams Green algae Ciliates Diatoms Red algae Amoebas Cellular slime molds Euglena Trypanosomes Animals Leishmania Fungi
Body Plan • Fungi all consist of three basic body parts A) Mycelium • Mass of thread like hyphae that grow into media - body of organism • Used for digestion and absorption Go to: http://www.aw-bc.com/campbell/
Body Plan B) Fruiting Bodies • Reproductive (asexual usually) structures used for both reproduction and dispersal of the species • Located above the ground • Ex. A mushroom
Body Plan C) Spores • Haploid structures produced by meiosis • Asexual structures used for reproduction • Land adapted for species dispersal by air Spores on Penicillium sp.
Hyphae 1. Descending hyphae (rhizoids) used for extracellular digestion and absorption of nutrients - form the mycelium (body of the organism). Also involved in sexual reproduction by production of gametes which fuse to form a zygote.
Hyphae 2. Ascending Hyphae • These grow up from mycelium and produce sporangium (n) which produces multitudes of haploid spores by mitosis. • These are air borne so the ascending hyphae raises them as high as possible
Hyphae 3. Transverse Hyphae (stolons) • These typically grow parallel to soil and are used to asexually establish satellite colonies • Can also be be used for sexual reproduction • All multicellular fungi show these three types of specialized hyphae which illustrates land adaptation http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/Penicillium.jpg/300px-Penicillium.jpg
Fungal Life Cycle http://occawlonline.pearsoned.com/bookbind/pubbooks/campbell6e_awl/chapter31/deluxe.html
Spore Dispersal • Insects (e.g. fruit flies from one fruit to another) • Eaten and defecated by animals • Wind or air-born (e.g. bread mold) • Fluid filled “bulb” with spore packet propels, like a canon, to area where animals will eat. (e.g. Pilobolus – “hat thrower”)
Fungi Classification • Fungi were initially classified as plants so retain many plant related names. • Classified based upon their distinctive reproductive structures (sexual or asexual) • Three main groups called Divisions (rather than phyla). Currently, seven fungal divisions are proposed Zygomycota, Ascomycota, Basidiomycota
Division Zygomycetes • Mostly terrestrial living in soils and acting as decomposers. • Good at breaking down animal waste (feces) • The common bread mold Rhizopus sp. is used as a typical example of this division. www.rogers.k12.ar.us/users/ehutches/tigerbreadmold1.jpg
Division Ascomycetes • Largest group of fungi • All produce two types of spores: A) Ascospores: sexual spores within a specialized structure called an Ascus Ascospores inside an ascus of a cup fungus
Division Ascomycetes B) Conidiospores • These are asexual spores produced inside a sporangium called a Conidia • Located on ascending hyphae
Division Ascomycetes Truffles from Oregon • Include: • Sac fungus, lichens (fungus portion), truffles, Penicillium, Aspergillius Mold
Division Ascomycetes Various lichen types
Division Ascomycetes Penicillin sp. Cup Fungus
Division Basidiomycetes • Most advanced multicellular fungi • Reproduce asexually with basidiospores produced from sporangia called basidia • Examples include mushrooms and toadstools
Division Basidiomycetes • The mushroom is a typical basidiomycetes • Ascending hyphae grow together to form solid mass that allows basidia to be raised much higher • What we call the mushroom is really the fruiting body of the organism properly called a Basidiocarp.
Division Basidiomycetes • The cap covers and supports the gills. • The gills are made from the end of the ascending hyphae which terminate as basidia. • The gills provide massive surface area for spore development
Division Basidiomycetes • The basidia are club shaped structures that asexually produce the basidiospores. • These spores are released and distributed by air promoted by being elevated by the mushroom stalk. scarab.cordley.orst.edu/shrooms/webpages/text/images/ama_pac_micro.jpg
Division Basidiomycetes • Like most fungi, the basidiomycetes are decomposers • They are remarkable for their rapid growth in favorable conditions bcmushrooms.forrex.org/ntfp/images/introduction/diagrams/mushroom.jpg
Other Basidiomycetes Earth Star Puffballs Bracket Fungi
Importance of the Fungi 1. Decomposers • Along with bacteria, they are the worlds major recyclers of organic compounds • Can tolerate environments bacteria can’t ex. High acid
Importance of the Fungi 2. Diseases A) Plants • Plants are more susceptible to fungal infections than animals • Most common includes rusts and mold infections
Fungal Diseases B) Animal Diseases • Most fungi are opportunists in animals • Most common infections are to the skin and mucous membranes. Ex. Candida and Athletes foot www.healthegoods.com
Importance of the Fungi 3. Food: Many fungi are edible Truffles Mushrooms
Importance of the Fungi 4. Fermentation • Yeast convert sugar to alcohol and CO2 by fermentation. • This is widely used for making wine and beer but is also essential in making bread and other doughs that must rise by yeast. www.alientravelguide.com
Importance of the Fungi 5. Antibiotics • Many antibiotics come from molds. • Antibiotics are competitive inhibitors produced by certain fungi and bacteria • This Penicillin disk on the side of the Petri disc is inhibiting bacteria http://img301.imageshack.us/i/s58dryh9.gif/#q=fleming%20antibiotics
Importance of the Fungi 6. Symbiotic Fungi A) Mycorrhizae • These are fungi that grow with plant roots • This greatly increases root surface area for absorption • In return, fungi gets organic nutrients • Found in 95% of all plants
Importance of the Fungi B) Lichens • Symbiotic relationship between a fungi (ascomycetes) and filamentous green algae • Fungi provides a home and traps water and minerals for the algae • Algae provides food (organic compounds) for the fungus • Ecologically important as pioneer organisms • (end show)