Transcript Fungi
Fungi a. Chytridiomycota- Chytrids b. Zygomycota- Molds c. Glomeromycota- Arbuscular Mycorrhizae Alma Khan and Shannon Hayes Basic Structure of Fungi • Most species of fungi are multicellular • Most common body structures are multicellular filaments and single cells (yeasts) • Multicellular fungi are made up of hyphae • Hyphae may contain septa (divide hyphae into different cells, but contain pores) • Cells walls composed of chitin (some also include polysaccharides) • Fungi are composed of Eukaryotic cells. • Some fungi can maintain 2 different nuclei per cell, and some don’t have mitochondria. Structure Chytridiomycota: • Cells walls made mostly of chitin (but some are made of polysaccharide) • Only type of fungi to have flagella • Ribosomes are around a nuclei (not enclosed in a nuclear cap) • Smallest and simplest fungi. • Lack Septa Glomeromycota: • Lack Septa • Some form arbuscular mycorrhizae Zygomycota: • Cell walls composed mostly of chitin (sometimes polysaccharide) • Have a continuous mycelium containing hundreds or thousands of nuclei. • Lack Septa Diversity Chytridiomycota: • Sexual and asexual reproduction • Motile with Flagellated spores Zygomycota: • Sexual spores are thick, therefore resisting zygospores • Long multinucleate haploid hyphae Glomeromycota: • Form arbuscular mycorrhizae with plants Basics of Nutrition • Heterotrophs • Gain food by secreting powerful hydrolytic enzymes into their surroundings which brake down complex molecules into smaller organic compounds that the fungi can absorb and store. • Can act as decomposers, parasites or have a mutualistic relationship. Mode of Nutrition Chyridiomycota: • They derive nutrients from decaying in water and damp organic enriched habitats. Zygomycota: • Derives nutrients from the organic material it molds on. Glomeromycota: • Get nutrients from their mutualistic relationship with the plant they’ve pushed their hyphae into. Basics of Reproduction • Fungi reproduce by producing spores, either sexually or asexually. • Fungal nuclei are normally haploid, except for when they’re diploid during sexual reproduction. • Sexual reproduction requires the fusion of hyphae from different mating types (communicated through pheromones) • Process of asexual reproduction varies widely among fungi (some grow filamentous fungi that produces haploid spores by mitosis while in others, theirs is ordinary cell division or by the pinching of small “bud cells” of a parent cell. Reproduction of Zygomycota Reproduction Chytridiomycota Glomeromycota Ecological Significance Chytridiomycota: • Causing a global decline in amphibian species that inhabit freshwater ecosystems by causing fatal fungal infections. • Beneficial forms include the fungi found in the intestines of cattle that help them process the plant matter they eat. Glomeromycota: • Form a mutualistic relationship with almost 90% of all plant species through Arbuscular Mycorrhizae (supplies minerals and other nutrients to the roots of the plant, and “food” the fungus.) Zygomycota: • Live close to plants, usually in soil or decaying matter. • Contribute to the carbon cycle by decomposing soil, plant matter, and waste. • Cause serious infections in humans (specifically harmful for diabetics and those with weakened immune systems), such as Zygomycosis. Uniqueness Chytridiomycota: • Smallest and simplest fungi. • First found in northern Russia. • Believed to be the earliest fungal group to diverge from other fungi. • Only fungal group to have flagellum present. • Spores called zoospores Zygomycota: • Make up about 1% of fungi. • Most primitive terrestrial fungi. • Named for their sexually produced zygosporangia. • Some have structures that can withstand excessive droughts or extreme temperatures. Glomeromycetes: • Once considered Zygomycetes • Form arbuscular mycorrhizae Examples Chytridiomycota: • Orpinomyces joyoniifound in the intestines of cattle. • Allomyces anomalus- can withstand extreme temperatures. • Synchytrium endobioticum- a species that causes the “potato wart”. Examples Zygomycota: • Molds that are on strawberries and other fruits • Black Bread Mold Examples Glomeromycota: 1. Mycorrhizae formed by Glomeromycota are found in the majority of plants found on land. 2. Not as diverse as other types of fungi. Name Motile (move with flagella/ undulipodia) Habitat Chytridiomycota Yes Zygomycota Glomeromycota Cell Organization Reproductive Structures # of Species Known Septa Between Cells? Mostly Aquatic Unicellular or Filamentous Microscopic Sporangium 1,000 No No Mostly Terrestrial Filamentous Zygospores 1,000 No No Mostly Terrestrial (Plants) Filamentous Spores that resemble Zygospores 160 No References Bibliography Campbell, N. A., & Reece, J. B. (2008). Biology 8th Edition. New York: Benjamin-Cummings Pub Co. Chytridiomycota. (2010, August 7). Retrieved Febuary 21, 2012, from MicrobeWiki: http://microbewiki.kenyon.edu/index.php/Chytridiomycota Farabee, M. (2010, May 18). Biological Diversity: Fungi. Retrieved Febuary 21, 2012, from Biological Diversity 4: www.emc.maricopa.edu/faculty/farabee/biobk/biobookdiversity_4.html Slot, J. (2005, August 31). Mushrooms, Molds, and Much More: an introduction to fungal biology. Retrieved Febuary 21, 2012, from Teaching the Fungal Tree of Life: http://www.clarku.edu/faculty/dhibbett/TFTOL/content/1introprogress.ht ml#chytridiomycota Zygomycota. (2010, August 7). Retrieved Febuary 21, 2012, from MicrobeWiki: http://microbewiki.kenyon.edu/index.php/Zygomycota