By Sarah Z, Maddie, Sarah S, Flippy, Graham, and Gina Fungi By Sarah Z, Maddie, Sarah S, Flippy, Graham, and Gina
Fungi Overview Characteristics Evolution Structure Reproduction Sac Fungi Yeasts Club Fungi Smuts and Rusts Imperfect Fungi
Characteristics Kingdom Fungi contains 80,000 species Mostly multicellular eukaryotes that share a common mode of nutrition Heterotrophic Cells release digestive enzymes and then absorb resultant nutrient molecules Some are parasitic Several have mutualistic relationship
Structure Body (thallus) of most fungi is multicellular mycelium (yeasts are unicellular) Consists of a vast network of thread-like hyphae Septate fungi have hyphae with cross walls Nonseptate fungi are multinucleated Hyphae grow from tip Cell walls of chitin, like insect exoskeleton Excess food stored as glycogen as in animals Possibly evolved from red algae - both lack flagella
Structure Hypha Septum Structure Nuclei Mycelium
Reproduction Both sexual (in most) and asexual reproduction Sexual reproduction involves three stages: Haploid Hyphae Dikaryotic Stage Diploid Zygote
Reproduction During sexual reproduction, hyphae from two different mating types fuse Hyphae that contain paired haploid nuclei are said to be dikaryotic Nuclear fusion produces diploid nucleus, which produces haploid windblown spores by meiosis Spores germinate directly into haploid hyphae without embryological development Asexual reproduction usually involves the production of windblown spores Unicellular yeasts reproduce by budding
Chytridiomycota The chytrids are the most primitive of the fungi and are mostly saprobic (degrading chitin and keratin ) There are approximately 1,000 chytrid species, in 127 genera, distributed among 5 orders Both zoospores and gametes of the chytrids are mobile by their flagella, one whiplash per individual The thalli are coenocytic and usually form no true mycelium (having rhizoids instead) Some species are unicellular Ex: Water Molds
Zygomycota Zygospore Fungi Phylum Zygomycota Mainly saprotrophs decomposing animal and plant remains Black bread mold - Rhizopus stolonifer
Basidiomycota Phylum Basidomycota – 22,000 species Familiar toadstools, mushrooms, bracket fungi, puffballs, stinkhorns – some deadly poisonous Also plant diseases such as the smuts and rusts Mycelium composed of septate hyphae
Ascomycota Sac Fungi: About 60,000 species of sac fungi Most are saprotrophs that digest resistant materials containing cellulose, lignin, or collagen Most are composed of septate hyphae Neurospora, experimental organism for the one-gene-one-enzyme studies Morels and truffles, famous gourmet delicacies revered throughout the world Many plant diseases: Powdery mildews; leaf curl fungi; ergot of rye; chestnut blight and Dutch elm disease Aspergillus and Candida cause serious human infections Talaromyces (formerly Penicillium) is source of penicillin
Sac Fungi
Ascomycota Yeasts: Term “yeasts” is loosely applied to unicellular fungi, many of which are ascomycetes Budding is common form of asexual reproduction Sexual reproduction results in the formation of asci and ascospores When some yeasts ferment, they produce ethanol and carbon dioxide
YEAST
Lichens Three morphological types Compact crustose lichens - seen on bare rocks or on tree bark Fruticose lichens – shrub-like Foliose lichens - leaf-like Can live in areas of extreme conditions and contribute to soil formation Sensitive indicators of air pollution
Lichen
Fungi Phylogeny
FUNGI! 80,000 Heterotrophism Thallus Haploid Hyphae Dikaryotic Stage Diploid Zygote Septate Nonseptate False True Budding Animal and plant remains 22, 000 Basidiomycota Septate hyphae 60,000 Ethanol and Carbon Dioxide Linchens Chytridiomycota 20. Linchens seen on bare rocks or on tree bark Compact crustose Fruticose Foliose Zygomycota Basidiomycota and Ascomycota