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Unformatted text preview: Lab 2: Kingdom Fungi and Lab 2: Kingdom Fungi and Lichens
• Kingdom Fungi
• • • overview reproduction classification • lichens Kingdom Fungi: Overview Kingdom Fungi: Overview
unicellular to multicellular • cell walls primarily chitin • heterotrophic
• • secrete digestive enzymes (external digestion) • important decomposers • if multicellular: Kingdom Fungi: Overview Kingdom Fungi: Overview • hyphae – long, slender cellular filament • mycelium – mass of hyphae • reproduction mainly by spores (both sexual and asexual) Kingdom Fungi: Kingdom Fungi: Reproduction • spores somewhat resistant to harsh environmental conditions • spore germination mainly upon exposure to water • • sexual spore terms vary Kingdom Fungi: Kingdom Fungi: Reproduction asexual spores = conidia, formed on conidiophores • Asexual (imperfect stage) Kingdom Fungi: Kingdom Fungi: Reproduction • spores formed by mitosis • some fungi exhibit only asexual reproduction (imperfect fungi) • Sexual (perfect stage) Kingdom Fungi: Kingdom Fungi: Reproduction • gametes are produced in the gametangia • zygotic meiosis, with modifications…. Zygotic Meiosis – zygote Zygotic Meiosis – zygote directly undergoes meiosis
gametes 1N 1N 1N meiosis
2N (zygote) • zygotic meiosis, with modifications….
• plasmogamy • cells fuse their plasma membranes • results in dikaryotic cells if nuclei do not fuse (N+N instead of true diploid) • nuclei fuse, making a true diploid (2N) • this makes the zygote that undergoes meiosis Kingdom Fungi: Kingdom Fungi: Reproduction • karyogamy 6 Major Groups of Fungi: Kingdom Fungi: Kingdom Fungi: Classification – Phylum Chytridiomycota* – Phylum Zygomycota* – Phylum Glomeromycota* – Phylum Ascomycota: sac fungi – Phylum Basidiomycota: club fungi – Imperfect Fungi: asexual reproduction only *not covered in detail in Biol 1031 lab defined by special structure for sexual Phylum Zygomycota Phylum reproduction – a resistant ball called a zygosporangium where meiosis occurs and meiospores are formed mainly asexual reproduction (conidia, conidiophores) Phylum Zygomycota Phylum includes bread molds tasks: – look at the example, Rhizopus – DO NOT open the Rhizopus cultures, they can be very dangerous if inhaled Phylum Ascomycota: sac fungi Phylum defined by ascus (saclike sporangium) asexual reproduction common as well – karyogamy occurs to form zygote – meiosis forms ascospores in a sac – sac breaks open to release spores Phylum Ascomycota: sac fungi Phylum Tasks: – look at examples: preserved Bulgaria – complete the Ascomycete life cycle on 2.3 slide 21 Peziza look for asci, ascospores Imperfect Fungi Imperfect Fungi fungi with no known sexual reproduction (only asexual) Slides:
– 23 Penicillium – 24 Aspergillus observe conidiophores and conidia; also note septate (crosswalled) Phylum Basidiomycota: Club fungi Phylum includes mushrooms, toadstools, shelf fungi, stinkhorns, and puffballs defined by basidium (clublike sporangium) little asexual reproduction – karyogamy occurs to form zygote – meiosis forms basidiospores at tip of club – spores pinch off from club for release Phylum Basidiomycota: Club fungi Phylum Tasks: – look at preserved specimens and learn parts of a typical basidioma (fruiting body) – also investigate slide 22 Psilocybe – complete the Basidiomycota life cycle on 2.6 cap (pileus), stipe (stalk), gills (lamella), ring (annulus) should be visible Lichens Lichens symbiotic relationship between: usually mutualistic (both benefit) – a heterotrophic fungus (mycobiont) – and an autotrophic alga or bacterium (photobiont) – fungi offer shelter from the harsh environment – photobiont produces food through photosynthesis Lichens Lichens There are 3 forms of lichens: – crustose crustlike – foliose leaflike – fruticose shrublike, or fruitlike – be able to identify the three forms QUESTIONS? QUESTIONS? ...
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