Biology reading for 4/6/15Chapter 10 FungiInvestigating the structure and evolutionary history of fungiFungi are heterotrophs that feed by absorptionMany grow by forming multicellular filamentsNutrition and ecologyFungi are heterotrophs. Some absorb nutrients from the environment outside of the body. Others use enzymes to penetrate cell walls and absorb nutrients from the cell.Body StructureYeasts: single cells in fungi. Supplies sugars and amino acidsHyphae: tiny filaments that consists of tubular cell walls surrounding the plasma membrane and cytoplasmChitin: strong but flexible polysaccharideChitin-rich walls enhance feeding by absorptionSepta: cross-walls that divides hyphae into cellsCoenocytic fungi: lacks septa. It consists of a continuous cytoplasmic mass containing hundredsor thousands of nuclei.Mycelium: an interwoven mass that infiltrates the material on which the fungus feedsSpecialized hyphae in mycorrhizal FungiHaustoria: Specialized hyphae which fungi use to extract nutrients from, or exchange nutrients with their plant hosts. Mycorrhizae: “fungus roots”. Benefical relationships between fungi and plant rootsMycorrhizal fungi: fungi that form mycornhizaeMycorrhizal fungi can improve the delivery of phosphate ions and other materials to plants because the mycelial networks are more efficient than plant roots.Plants supply the fungi with organic nutrients such as carbohydrates.Two types of mycorrhizal fungi: Ectomycorhizal fungi and arbuscular mycorhizal fungiEctomycorhizal fungi: form sheaths of hyhae over the surface of a root and typically grow into the extracellular spaces of the root cortexArbuscular mycorhizal fungi: extend branching hyphae through the root cell wall and into tubes formed by invagination of the root cell membraneAlmost all vascular plants have mycorrhicae and rely on fungi for nutrientsSpore: haploid cells that form mycelia after germinatingQuizlet link:
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