Biology Lab Notes Fungi

* Fungi are Eukaryotic, mainly multi cellular organisms includes molds and mushrooms * fungi lack chlorophyll * they are heterotrophic and cell walls contain chitin * more closely related to animals * supergroup Unikonta categorized as opisthokonts bc of single posterior flagellum * heterotrophs, secrete enzymes which digest food outside the body, the broken down food is then absorbed by hyphae * 3 types of fungi * decomposer fungi, absorb nutrients from nonliving sources * parasitic fungi: absorb nutrients form living sources * mutualistic fungi: both fungus and host organism benefit from relationship (example is mycorrhizal fungus and plant roots) * Mycelium is made up of threads called hyphae. * hyphae may have septate ( cross walls that separate nuclei and cytoplasm into cells) * hyphae may be coenocytic which means lack of such cross walls * Sexual reproduction occurs only when mycelia of different mating strains meet and fuse * plasmogamy: the union of the cytoplasm of the two gamete cells * karyogamy: the union of the nuclei * dikaryon (unfused) refers to the nuclei * fungus is all haploid, only diploid life cycle is the zygote. zygote undergoes meiosis to produce haploid spores for dispersal * molds: fungi in vegetative state (Deuteromycota/ fungi imperfecti * fungi are classified into 5 phyla * Chytridiomycota: spores with flagella * the rest named after the reproduction structures formed * Zygomycota: produces zygosporangia * bread molds: Rhizopus * 3 types of hyphae * stolon hyphae: cover surface of bread * rhizoid hyphae: penetrate the bread and absorb nutrients * Sporangiophores: stand upright bearing spores at tips * sexual reproduction occurs when opposite mating ypes (+-) of hyphae come together. *