BIOL 172L EXAM 1 UH MANOA QUESTIONS WITH 100% VERIFIED SOLUTIONS!!

plasmogamy - Mycelia of different types fuse together in plasmogamy (a stage where two parent mycelia fuse but the nuclei do not fuse) to form a dikaryotic mycelium that grows quickly and crowds out the haploid parental mycelia. The dikaryotic mycelium forms compact masses that develop into basidiocarps. These basidiocarps are fruiting bodies that arise in response to environmental stimuli. Basidium/Basidiospore - The basidiocarp contains basidia (singular: basidium) cells where karyogamy occurs. The mushroom cap supports and protects a large surface area of dikaryotic basidia on its gills. Karyogamy produces a diploid nucleus in the basidium that undergoes meiosis to produce four haploid nuclei. The haploid nuclei then develop into basidiospores. Algae - -Eukaryotic • Aquatic • Photo-autotrophs • Unicellular and multi-cellular forms Fungi - • Eukaryotic • Acquire food via absorption • Heterotrophic - Saprobic (decomposers) - Parasitic - Symbiotic • Cell walls composed of chitin • Are now a monophyletic group Taxonomic Categories -Zygomyta - example: Bread mold, Reproduction: Majority are Asexual, some are sexual Structure of Fungi - Cell walls composed of chitin • Thallus composed of hyphae - septate or coenocyntic • Mycelium (root part) is the vegetative part of a fungus, composed of branched hyphae • Mycelia are interwoven throughout food source • Fruiting body (e.g. mushroom)(top of mushroom) is the reproductive structure two types of hyphae. Any given fungal species will have only one type - -Septate: the hyphae are divided into cells by cross-walls called septa -Coenocytic (= aseptate): the hyphae are not divided by septa, but consist of continuous cytoplasm with hundreds of nuclei Fungi: Generalized Life Cycle - Though their reproductive structures vary in appearance, all fungi have the same generalized life cycle. The nuclei in the hyphae of the mycelium are haploid. Fungi reproduce by releasing spores that are produced either sexually or asexually: Fungal Divisions - 4 divisions (= phyla) in the Kingdom Fungi: Chytridmycota, Basidiomycota, Ascomycota, Zygomycota (remember A,B,C,Z)Zygomycota - Mycelium mainly coenocytic (aseptate) • Many disperse aerial spores (asexual reproduction) • Forms zygosporangia when food is in short supply (sexually reproduction) • E.g. molds Its hyphae are mainly aseptate with cross-walls only separating where reproductive cells are formed. Rhizopus mainly reproduces asexually. Asexual reproduction occurs when upright hyphae develop bulbous black sporangia (singular: sporangium) at their tips. Within each sporangium, hundreds of haploid spores develop and are then dispersed through the air. These spores can travel to other areas containing food and begin growing into new mycelia. Rhizopus are capable of reproducing sexually, which they usually choose to do when food sources become scarce Zygomycota Reproduction - Ascomycota - "Sac Fungi" • Produce spores in saclike asci • Includes - true yeasts - ascomycetes that produce ascocarps (e.g. morels, truffles) -Unlike most ascomycetes, yeast do not form multicellular mycelia. Instead, they are unicellular. (budding)