Chapter 22 Opisthokants group of fungi animals and choanoflagellates modes of nutrition Saprobes absorb nutrients from dead organic matter Parasites absorb nuterients from living hosts Mutualists benefit both partners fungi evolved from unicellular protist that had falgellum Unicellular free living fungi are yeasts Body of multicellular fungi mycelium composed of individal tubular filaments hyphae hyphae subdivided into cell like ocmpartments by incomplete cross walls septa other species have hundreds of nuclei coenocytic and no septa Fungi have tolerance for highly hypertonic environmental Saprobic fungi are major decomposers on earth no decomposers no carbon cycle on earth produce spores Facultative parasites grow on living organisms but can grow by themselves Obligate parasites only grow on specific living host Lichens association of fungi with cyanobacteria photosynthetic alga or both susceptible to poor air quality but can survive in harsh environments body forms crustose crustlike lichens look like colored poweder dusted over substrate foliose leafy fructicose shrubby reproduce by fragmentation of vegetative body thallus or by specialized structures soredia Mycorrhizae association of fungi and roots of plants fungus obtais material and provides minerals and water to plant endomycorrhizae fungus wraps around root dont penetrate cell walls increase surface area for absorption of water minerals arbuscular mycorrhizae enter root and penetrate cell walls of root cells form arbuscular treelike structure inside cell wall fungus provides better absorption of H20 and obtains organic compounds from plant may provide plant with growth hormones and protection from disease causing microbes plants that lakc chlorophyll have mycorrhizae Endophytic fungi fungi that live within plants and don t cause obvious deleterious symptoms 6 major groups of fungi microsporidia chytrids zygospore fungi arbuscular mycorrhizal fungi sac fungi club fungi Asexual reproduction forms production of haploid spores within structures called sporangia production of haploid spores at tips of hyphae called conidia Cell division by unicellular fungi fission equal division of cell into 2 budding asymmetrical division in which smaller daughter cell produced Individuals of same mating type cannot mate can mate with other mating type of same species Microsporidia unicellular parasitic fungi lack mitochondria have reduced structures mitosomes mitosomes contain no DNA hots cell penetrated by polar tube that grows from microsporidian spore contents injected into cell called sporoplasm cytoplasms of two individuals of different mating type fuse plasmogamy before nuclei Zygospore resting stage undergoes meiosis to become sporangiophore Sporangiophore fruiting structure chytrids possess flagellated gametes only fungi to have flagella at any lie cycle stage reproduce both asex And sex Parasitic and mutualistic Other 4 fuse karyogamy Arbuscular mycorrhizal fungi Symbiotic mutualistic relationship with plants hyphae coenocytic reproduce asex Last 2 stage is dikaryon ploidy indicated by n n Sac fungi Club fungi distinguished by production of sacs called asci septate hyphae Basidium swollen cell at tip of specialized hypha is characteristic basidiomata fruiting structure basidia reproductive structure two genetically different haplod nuclei co exist and divide within each cell of mycelium