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level: Level 1 of Reproduction of Mycetes

Questions and Answers List

level questions: Level 1 of Reproduction of Mycetes

QuestionAnswer
Talk in general about fungal reproductionFungal reproduction occurs in a variety of ways asexually and sexually using different strategies. Fungi that reproduce sexually have a haploid stage and a diploid stage (short-lived) in their life cycles. Ascomycetes and Basidiomycetes also go through a dikaryotic stage, in which the nuclei inherited by the two parents do not fuse right away, but remain separate in the hyphal cells.
Talk about Asexual reproduction of fungi (Budding and fragmentation)Asexual reproduction is carried out by budding, fragmentation, or, most commonly, by spore formation. - Budding: as in single celled yeast (Saccharomyces) - Fragmentation: Mycelial fragmentation occurs when a fungal mycelium separates into pieces with each component growing into a separate new mycelium. e.g. Basidiomycota
Talk about asexual reproduction of fungi (spore formation)Spores are quite small and easily carried by wind. Reproductive structures involved in the production of spores are called sporangia. These sporangia are located at the tip of hyphae from which they are separated by complete septa. Spores are the primary means of reproduction, dispersal and survival. Spores are resting resistant stages (cysts) under unfavorable conditions and are in an active stage under favorable conditions. Spores could be exogenous, called conidia, (e.g. Penicillium) or endogenous, produced inside sporangia (e.g. Rhizopus). Spores of fungi are non-flagellated (aplanospores).
Talk about deuteromycota reproductionDeuteromycetes (Imperfect fungi) reproduce asexually by producing conidia. They have no known sexual reproduction.
Talk about ascomycota reproductionIn Ascomycetes, sexual reproduction begins when the hyphae of two different strains of sac fungi become closely associated. Antheridia are formed on the mycelium of (-) strain and oogonia on the other one (+). The male nuclei of the antheridium pass into the ascogonium via the trichogyne which is an outgrowth of the ascogonium (2) and pair with the female nuclei present but do not unite - Plasmogamy takes place. New dikaryotic hyphae (= dikaryon) develop from this fused structure (3). The cells at the tip of these hyphae form asci (sing. ascus), sac like structure (4), in which karyogamy (nuclear fusion) occurs. These asci (along with the sterile filaments paraphyses) are embedded in an ascocarp, the fruiting body of the fungus. Karyogamy in the asci is followed immediately by meiosis (5) and the production of ascospores (endogenous) (6, 7). The ascospores are disseminated (8) and germinate (9) to form new haploid mycelium. Asexual conidia may be produced by the haploid mycelium (10). In this life cycle, plasmogamy and karyogamy are separated in time and space by a dikaryotic phase.
Talk about deuteromycota sexual/asexual reproductionThey are referred to as imperfect fungi; their sexual form of reproduction has never been observed. Imperfect fungi reproduce asexually by producing conidia on specialized hyphae called conidiophores.