CAS BI 108 Lecture Notes - Lecture 3: Dimorphic Fungus, Hypha, Mycorrhiza
Document Summary
Ecologically and economically important because: nosocomial infections, plant pathogens, food chain/decomposers, digestion, medicine, food and produce food, plant symbiots = the mycorrhizae. Mushroom = temporary above ground reproductive structure: pilus (stalk, cap, gills. Similarities: grow in ground, sessile, have a cell wall. Differences: cell wall made of chitin, lack chloroplasts. Life cycle of a fungus: haploid phase. Start with haploid spores formed by meiosis. Spores germinate and grow into haploid mycelia. Cells haploid, undergo mitosis to form fungal body. Fusion of two mating types, exchange of nuclei. Terminal cells of hyphae become sporangia (pair of haploid nuclei) Two haploid nuclei fuse to finally become zygote. Zygotes form in specialized cells on underside of cap called sporangia (sporangium) Zygotes undergo meiosis in sporangia to produce haploid spores. Fungi are classified into 3 basic groups based on reproduction: zygomycota (ex. Coprinus: deuteromycota = the false fungi, most pathogenic.