BIO 121 Lecture Notes - Lecture 20: Mycelium, Karyogamy, Protist
Document Summary
The body of the parental fungi (mycelium, hyphae) is haploid. Heterokaryotic cells have multiple genetically unique nuclei. Haploid fruiting bodies form haploid spores that grow into haploid mycelium by mitosis. Karyogamy and meiosis produce genetic variation during sexual reproduction. The ancestor of fungi was an aquatic, single-celled flagellated protist. Fungi and animals are more closely related to each other than fungi and plants. Fungi were among the earliest colonizers of land. About 1000 species (terrestrial, freshwater, marine habitats) They produce unique spores ( zoospores ) that swim w/ flagellum. Reproduce using zygospores that form inside a zygosporangium that resists freeing/drying. Nearly all 160 species form mycorrhizae w/ plants. Exchange minerals/nutrients with the plant root -- done w/ structures called arbuscules. 65,000 species live in marine, freshwater and terrestrial habitats. neurospora is a model organism used extensively in genetics research. Vary in size and complexity. some are plant pathogens, decomposers and symbionts. Many make enzymes that can digest and decompose wood.