{"id":79,"date":"2015-07-17T22:02:35","date_gmt":"2015-07-17T22:02:35","guid":{"rendered":"https:\/\/courses.candelalearning.com\/bio2labsxmaster2\/?post_type=chapter&p=79"},"modified":"2016-01-06T22:04:59","modified_gmt":"2016-01-06T22:04:59","slug":"79","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/tcc-biolab\/chapter\/79\/","title":{"raw":"Reading: Fungi","rendered":"Reading: Fungi"},"content":{"raw":"

Zygomycota<\/h2>\r\nFungi in the phylum Zygomycota are called zygomycetes.\u00a0The zygomycetes are terrestrial. They are usually saprotrophs<\/strong> but there are some parasites.<\/strong>\u00a0The hyphae are coenocytic (theyn lack septa). Septa are found only in the reproductive structures.\r\n

Reproduction in Zygomycota<\/h3>\r\nFusion of two hyphae leads to the formation of a zygosporangium<\/strong>, a thick-walled structure that is capable of surviving environmental extremes. Before karyogamy, the zygosporangium contains many haploid nuclei. after karyogamy, it contains many diploid nuclei.\r\n\r\n\"zygomycota2\"\r\n

Rhizopus (Bread Mold)<\/h3>\r\n[caption id=\"attachment_275\" align=\"alignright\" width=\"300\"]\"Figure Figure 2. Rhizopus* sporangia[\/caption]\r\n\r\nAsexual reproduction involves mycelia producing sporangia that produce haploid spores by mitosis. The spores produce new mycelia.\r\n\r\n[caption id=\"attachment_276\" align=\"alignright\" width=\"300\"]\"img002\" Figure 3. Rhizopus* zygotes[\/caption]\r\n\r\nWhen environmental conditions deteriorate, sexual reproduction may occur. Hyphae from opposite mating types produce structures that contain several haploid nuclei. Fusion of two of these structures from opposite mating types results in a heterokaryotic zygosporangium<\/b>. A thick wall develops that functions to protect the zygospore until environmental conditions become favorable. When conditions are favorable, nuclear fusion (karyogamy) occurs within the zygosporangium producing diploid nuclei. This is followed by meiosis. The zygosporangium then germinates to produce a sporangium which releases haploid spores.\r\n\r\nObserve Rhizopus<\/i> (bread mold) growing on a culture dish. Use a dissecting microscope to see details of the hyphae and sporangia. Is there any evidence of sexual reproduction?\r\n

Phylum: Ascomycota (Sac Fungi)<\/h2>\r\nExamples: Yeasts, molds, morels, truffles<\/em>\r\n\r\n[caption id=\"attachment_277\" align=\"alignright\" width=\"200\"]\"Figure Figure 4. Morels (left) are sac fungi. Photo courtesy of Michael Lawliss.[\/caption]\r\n\r\nAscomycetes are important in digesting resistant materials such as cellulose<\/strong> (found in plant cell walls), lignin (found in wood), and collagen<\/strong> (a connective tissue found in animals). This group also includes many important plant pathogens.\r\n\r\nMany, perhaps half of the species of ascomycota form lichens\u2014a symbiotic relationship between a fungus and a photosynthetic cell such as a green algae or a cyanobacteria. The fungal component of most lichens is an Ascomycete.\r\n

Reproduction in Sac Fungi<\/h3>\r\n

Sexual<\/h4>\r\nHyphae from opposite mating types fuse, forming a heterokaryotic structure which then produces dikaryotic hyphae.\r\n\r\nThe fruiting body is called an ascocarp<\/b>. It is composed of dikaryotic hyphae and haploid hyphae.\r\n\r\n\"ascomycota\"\r\n\r\nDikaryotic hyphae within the ascocarp produces asci<\/b> (singular: ascus<\/b>), sacs that are walled off from the rest of the hyphae. Nuclear fusion within an ascus will produce a diploid zygote. The zygote will undergo meiosis, followed by mitosis\u00a0to produce 8 haploid ascospores<\/strong>.\r\n\r\n\"img004\"\r\n\r\nAsci with ascospores can be seen in figure 5.\r\n\r\n[caption id=\"attachment_280\" align=\"alignnone\" width=\"320\"]\"Figure Figure 5. Peziza cross section X 200.[\/caption]\r\n

Asexual<\/h4>\r\nMost reproduction is by asexual spores called conidia<\/strong>. Unlike the Zygomycetes which produce asexual spores within sporangia, conidia are produced on the ends of specialized hyphae called conidiophores.\r\n

Examples of Sac Fungi<\/h3>\r\nMorels and truffles are gourmet delicacies.\u00a0This group includes many important plant parasites such as Dutch elm disease, chestnut blight, leaf curl fungi, and Claviceps<\/i>.\r\n\r\nAn ergot is the hard, purple-black fungus Claviceps purpurea<\/i>. It contains toxic alkaloids, including LSD. When infected rye is made into bread, the toxins are ingested and cause vomiting, muscle pain, feeling hot or cold, hand and foot lesions, hysteria and hallucinations. Historians believe that those that accused their neighbors of witchcraft in Salem may have been suffering from ergotism. Claviceps<\/i> is used to stimulate uterine contractions and to treat migraine headaches.\r\n

Peziza (Cup Fungi)<\/h3>\r\nObserve preserved Peziza<\/i> (cup fungus) using a dissecting microscope.\r\n\r\nObserve a slide of\u00a0 Peziza<\/i> at scanning, low, and high power magnification. Find an ascus and ascospores on the upper surface (inside the cup).\r\n

Aspergillus<\/h3>\r\nObserve the conidiophores and conidia<\/strong> (asexual spores) of Aspergillus<\/em>.\r\n

Yeast<\/h3>\r\nYeast are single-celled members of the sac fungi.\u00a0Most reproduction is asexual; a small cell pinches off from a larger cell. This type of mitosis where a smaller individual grows from a larger individual is called budding<\/i>.\r\n\r\nMake a wet mount of live yeast and see if you can observe budding under high power. If you cannot see yeast budding, view a prepared slide of yeast budding under high power.\r\n\r\nYeast also reproduce sexually by forming an ascus and eight ascospores. View a slide of Schizosaccharomyces octosporus under high power or oil immersion and find an ascus with ascospores.\r\n\r\n[caption id=\"attachment_282\" align=\"alignnone\" width=\"842\"]\"Figure Figure 6. Yeast (Saccharomyces) budding X 1000.[\/caption]\r\n\r\nDuring sexual reproduction, the fusion of two cells results in the formation of an ascus.\r\n\r\n[caption id=\"attachment_283\" align=\"alignnone\" width=\"208\"]\"Figure Figure 7. Schizosaccharomyces octosporus X 1000[\/caption]\r\n\r\nThe elongated cell in the upper left part of figure 7 contains\u00a0 ascospores.\r\n\r\n[caption id=\"attachment_284\" align=\"alignnone\" width=\"343\"]\"Figure Figure 8. Schizosaccharomyces octosporus X 1000[\/caption]\r\n\r\nCells in the lower left part of the figure 8 contain ascospores.\r\n\r\nYeast is\u00a0important in leavening bread by CO2<\/sub> production and in producing ethanol for alcoholic beverages.\r\n

Penicillium<\/h3>\r\nObserve Penicillium<\/i> growing on a culture dish.\r\n\r\n[caption id=\"attachment_289\" align=\"alignnone\" width=\"400\"]\"Penicillium Figure 9. Penicillium growing on an agar plate[\/caption]\r\n\r\nPenicillium<\/i> reproduces asexually. Observe a slide of Penicillium<\/i> conidiophores<\/b> under high power. The spores are called conidia<\/b>.\r\n\r\n[caption id=\"attachment_281\" align=\"alignnone\" width=\"320\"]\"Figure Figure 10. Penicillium Conidiophores and conidia X 400.[\/caption]\r\n

Phylum: Basidiomycota (Club Fungi)<\/h2>\r\n

Reproduction<\/h3>\r\nAsexual reproduction in club fungi is rare.\u00a0Their fruiting bodies are called basidiocarps<\/strong>. This is the visible mushroom<\/em>.\r\n\r\n[caption id=\"attachment_285\" align=\"alignright\" width=\"300\"]\"Figure Figure 11. Mushrooms showing gills[\/caption]\r\n\r\nSpores, called basidiospores<\/strong> are produced on basidia<\/strong> within the basidiocarps. In mushrooms, the basidia are located along the gills on the underside of the cap. In figure 6, a portion of the cap of this mushroom has been broken away to reveal the gills.\r\n\r\n\"basidiomycota\"\r\n\r\n\"img005\"\r\n\r\n[caption id=\"attachment_288\" align=\"alignright\" width=\"300\"]\"Figure Figure 12. Basidia and basidiospores X 1000[\/caption]\r\n\r\nIn ascomycota<\/strong> (sac fungi), the ascospores<\/strong> were enclosed in an ascus. In basidiomycota, the basidiospores are not enclosed. Compare the diagrams of a basidium with basidiospores above with that of an ascus with ascospores seen earlier.\r\n\r\nBasidiospores germinate to produce monokaryotic (haploid, one nucleus per cell) hyphae. Mushrooms are composed of dikaryotic hyphae which are formed when hyphae fuse. Dikaryotic nuclei within the basidium fuse to produce a zygote and meiosis then produces basidiospores.\r\n\r\nObserve some representative club fungi on display including mushrooms, puffballs, and bracket fungi.\r\n

Bracket Fungi<\/h3>\r\n[caption id=\"attachment_291\" align=\"alignnone\" width=\"400\"]\"Figure Figure 13. Bracket fungi[\/caption]\r\n

Bracket Fungi and Lichens<\/h3>\r\n[caption id=\"attachment_292\" align=\"alignnone\" width=\"400\"]\"Figure Figure 14. Bracket fungi and lichens[\/caption]\r\n

Mushrooms<\/h3>\r\n[caption id=\"attachment_290\" align=\"alignnone\" width=\"400\"]\"Figure Figure 15. Mushrooms[\/caption]\r\n\r\nCut a mushroom to reveal the gills as shown in figure 16. Basidia and basidiospores form on the gills.\r\n\r\n[caption id=\"attachment_293\" align=\"alignnone\" width=\"400\"]\"Figure Figure 16. Mushroom cut to reveal the gills[\/caption]\r\n\r\nView a cross section of the cap of a mushroom (Coprinus<\/i>) showing the gills. Find a basidium and basidiospores.\r\n\r\n[caption id=\"attachment_294\" align=\"alignnone\" width=\"400\"]\"Figure Figure 17. Coprinus X 400[\/caption]\r\n\r\n[caption id=\"attachment_295\" align=\"alignnone\" width=\"400\"]\"Figure Figure 18. Coprinus X 1000 showing basidia and basidiospores[\/caption]\r\n

Symbiotic Associations of Fungi and Other Organisms<\/h2>\r\n

Lichens<\/h3>\r\nLichens are structures made up of two different species:\r\n
    \r\n\t
  1. a fungus<\/li>\r\n\t
  2. either a cyanobacterium or a green algae<\/li>\r\n<\/ol>\r\nThe photosynthetic cells are contained within the middle layer.\r\n\r\nThe photosynthetic cells provide photosynthesis for the lichen. It was thought that the relationship was mutualistic because the fungus prevented the algal cells from desiccation. Recent evidence indicates that the photosynthetic cells may grow faster when separated from the fungus. Perhaps the fungus is parasitizing the photosynthetic cells.\r\n\r\nReproduction is asexual. Fragments are produced that contain fungal hyphae and photosynthetic cells.\r\n\r\nLichens derive most of their water and minerals from rainwater and air. This allows them to survive on bare rock, tree trunks, inhospitable places.\r\n\r\nObserve the lichens on display. Some lichens have a crust-like appearance (crustose). Others have a shrublike (fruticose) or leaflike (foliose) appearance.\r\n\r\n[caption id=\"attachment_296\" align=\"alignnone\" width=\"400\"]\"Figure Figure 19. Lichens growing on a rock[\/caption]\r\n\r\n[caption id=\"attachment_297\" align=\"alignnone\" width=\"400\"]\"Figure Figure 20. Lichens growing on a tree[\/caption]\r\n\r\n[caption id=\"attachment_298\" align=\"alignnone\" width=\"400\"]\"Figure Figure 21. Lichens growing on a tree[\/caption]\r\n\r\n[caption id=\"attachment_299\" align=\"alignnone\" width=\"400\"]\"Figure Figure 22. Lichen thallus (cross-section X 200)[\/caption]\r\n\r\n[caption id=\"attachment_300\" align=\"alignnone\" width=\"400\"]\"Figure Figure 23. Lichen thallus X 400[\/caption]","rendered":"

    Zygomycota<\/h2>\n

    Fungi in the phylum Zygomycota are called zygomycetes.\u00a0The zygomycetes are terrestrial. They are usually saprotrophs<\/strong> but there are some parasites.<\/strong>\u00a0The hyphae are coenocytic (theyn lack septa). Septa are found only in the reproductive structures.<\/p>\n

    Reproduction in Zygomycota<\/h3>\n

    Fusion of two hyphae leads to the formation of a zygosporangium<\/strong>, a thick-walled structure that is capable of surviving environmental extremes. Before karyogamy, the zygosporangium contains many haploid nuclei. after karyogamy, it contains many diploid nuclei.<\/p>\n

    \"zygomycota2\"<\/p>\n

    Rhizopus (Bread Mold)<\/h3>\n
    \"Figure<\/p>\n

    Figure 2. Rhizopus* sporangia<\/p>\n<\/div>\n

    Asexual reproduction involves mycelia producing sporangia that produce haploid spores by mitosis. The spores produce new mycelia.<\/p>\n

    \"img002\"<\/p>\n

    Figure 3. Rhizopus* zygotes<\/p>\n<\/div>\n

    When environmental conditions deteriorate, sexual reproduction may occur. Hyphae from opposite mating types produce structures that contain several haploid nuclei. Fusion of two of these structures from opposite mating types results in a heterokaryotic zygosporangium<\/b>. A thick wall develops that functions to protect the zygospore until environmental conditions become favorable. When conditions are favorable, nuclear fusion (karyogamy) occurs within the zygosporangium producing diploid nuclei. This is followed by meiosis. The zygosporangium then germinates to produce a sporangium which releases haploid spores.<\/p>\n

    Observe Rhizopus<\/i> (bread mold) growing on a culture dish. Use a dissecting microscope to see details of the hyphae and sporangia. Is there any evidence of sexual reproduction?<\/p>\n

    Phylum: Ascomycota (Sac Fungi)<\/h2>\n

    Examples: Yeasts, molds, morels, truffles<\/em><\/p>\n

    \"Figure<\/p>\n

    Figure 4. Morels (left) are sac fungi. Photo courtesy of Michael Lawliss.<\/p>\n<\/div>\n

    Ascomycetes are important in digesting resistant materials such as cellulose<\/strong> (found in plant cell walls), lignin (found in wood), and collagen<\/strong> (a connective tissue found in animals). This group also includes many important plant pathogens.<\/p>\n

    Many, perhaps half of the species of ascomycota form lichens\u2014a symbiotic relationship between a fungus and a photosynthetic cell such as a green algae or a cyanobacteria. The fungal component of most lichens is an Ascomycete.<\/p>\n

    Reproduction in Sac Fungi<\/h3>\n

    Sexual<\/h4>\n

    Hyphae from opposite mating types fuse, forming a heterokaryotic structure which then produces dikaryotic hyphae.<\/p>\n

    The fruiting body is called an ascocarp<\/b>. It is composed of dikaryotic hyphae and haploid hyphae.<\/p>\n

    \"ascomycota\"<\/p>\n

    Dikaryotic hyphae within the ascocarp produces asci<\/b> (singular: ascus<\/b>), sacs that are walled off from the rest of the hyphae. Nuclear fusion within an ascus will produce a diploid zygote. The zygote will undergo meiosis, followed by mitosis\u00a0to produce 8 haploid ascospores<\/strong>.<\/p>\n

    \"img004\"<\/p>\n

    Asci with ascospores can be seen in figure 5.<\/p>\n

    \"Figure<\/p>\n

    Figure 5. Peziza cross section X 200.<\/p>\n<\/div>\n

    Asexual<\/h4>\n

    Most reproduction is by asexual spores called conidia<\/strong>. Unlike the Zygomycetes which produce asexual spores within sporangia, conidia are produced on the ends of specialized hyphae called conidiophores.<\/p>\n

    Examples of Sac Fungi<\/h3>\n

    Morels and truffles are gourmet delicacies.\u00a0This group includes many important plant parasites such as Dutch elm disease, chestnut blight, leaf curl fungi, and Claviceps<\/i>.<\/p>\n

    An ergot is the hard, purple-black fungus Claviceps purpurea<\/i>. It contains toxic alkaloids, including LSD. When infected rye is made into bread, the toxins are ingested and cause vomiting, muscle pain, feeling hot or cold, hand and foot lesions, hysteria and hallucinations. Historians believe that those that accused their neighbors of witchcraft in Salem may have been suffering from ergotism. Claviceps<\/i> is used to stimulate uterine contractions and to treat migraine headaches.<\/p>\n

    Peziza (Cup Fungi)<\/h3>\n

    Observe preserved Peziza<\/i> (cup fungus) using a dissecting microscope.<\/p>\n

    Observe a slide of\u00a0 Peziza<\/i> at scanning, low, and high power magnification. Find an ascus and ascospores on the upper surface (inside the cup).<\/p>\n

    Aspergillus<\/h3>\n

    Observe the conidiophores and conidia<\/strong> (asexual spores) of Aspergillus<\/em>.<\/p>\n

    Yeast<\/h3>\n

    Yeast are single-celled members of the sac fungi.\u00a0Most reproduction is asexual; a small cell pinches off from a larger cell. This type of mitosis where a smaller individual grows from a larger individual is called budding<\/i>.<\/p>\n

    Make a wet mount of live yeast and see if you can observe budding under high power. If you cannot see yeast budding, view a prepared slide of yeast budding under high power.<\/p>\n

    Yeast also reproduce sexually by forming an ascus and eight ascospores. View a slide of Schizosaccharomyces octosporus under high power or oil immersion and find an ascus with ascospores.<\/p>\n

    \"Figure<\/p>\n

    Figure 6. Yeast (Saccharomyces) budding X 1000.<\/p>\n<\/div>\n

    During sexual reproduction, the fusion of two cells results in the formation of an ascus.<\/p>\n

    \"Figure<\/p>\n

    Figure 7. Schizosaccharomyces octosporus X 1000<\/p>\n<\/div>\n

    The elongated cell in the upper left part of figure 7 contains\u00a0 ascospores.<\/p>\n

    \"Figure<\/p>\n

    Figure 8. Schizosaccharomyces octosporus X 1000<\/p>\n<\/div>\n

    Cells in the lower left part of the figure 8 contain ascospores.<\/p>\n

    Yeast is\u00a0important in leavening bread by CO2<\/sub> production and in producing ethanol for alcoholic beverages.<\/p>\n

    Penicillium<\/h3>\n

    Observe Penicillium<\/i> growing on a culture dish.<\/p>\n

    \"Penicillium<\/p>\n

    Figure 9. Penicillium growing on an agar plate<\/p>\n<\/div>\n

    Penicillium<\/i> reproduces asexually. Observe a slide of Penicillium<\/i> conidiophores<\/b> under high power. The spores are called conidia<\/b>.<\/p>\n

    \"Figure<\/p>\n

    Figure 10. Penicillium Conidiophores and conidia X 400.<\/p>\n<\/div>\n

    Phylum: Basidiomycota (Club Fungi)<\/h2>\n

    Reproduction<\/h3>\n

    Asexual reproduction in club fungi is rare.\u00a0Their fruiting bodies are called basidiocarps<\/strong>. This is the visible mushroom<\/em>.<\/p>\n

    \"Figure<\/p>\n

    Figure 11. Mushrooms showing gills<\/p>\n<\/div>\n

    Spores, called basidiospores<\/strong> are produced on basidia<\/strong> within the basidiocarps. In mushrooms, the basidia are located along the gills on the underside of the cap. In figure 6, a portion of the cap of this mushroom has been broken away to reveal the gills.<\/p>\n

    \"basidiomycota\"<\/p>\n

    \"img005\"<\/p>\n

    \"Figure<\/p>\n

    Figure 12. Basidia and basidiospores X 1000<\/p>\n<\/div>\n

    In ascomycota<\/strong> (sac fungi), the ascospores<\/strong> were enclosed in an ascus. In basidiomycota, the basidiospores are not enclosed. Compare the diagrams of a basidium with basidiospores above with that of an ascus with ascospores seen earlier.<\/p>\n

    Basidiospores germinate to produce monokaryotic (haploid, one nucleus per cell) hyphae. Mushrooms are composed of dikaryotic hyphae which are formed when hyphae fuse. Dikaryotic nuclei within the basidium fuse to produce a zygote and meiosis then produces basidiospores.<\/p>\n

    Observe some representative club fungi on display including mushrooms, puffballs, and bracket fungi.<\/p>\n

    Bracket Fungi<\/h3>\n
    \"Figure<\/p>\n

    Figure 13. Bracket fungi<\/p>\n<\/div>\n

    Bracket Fungi and Lichens<\/h3>\n
    \"Figure<\/p>\n

    Figure 14. Bracket fungi and lichens<\/p>\n<\/div>\n

    Mushrooms<\/h3>\n
    \"Figure<\/p>\n

    Figure 15. Mushrooms<\/p>\n<\/div>\n

    Cut a mushroom to reveal the gills as shown in figure 16. Basidia and basidiospores form on the gills.<\/p>\n

    \"Figure<\/p>\n

    Figure 16. Mushroom cut to reveal the gills<\/p>\n<\/div>\n

    View a cross section of the cap of a mushroom (Coprinus<\/i>) showing the gills. Find a basidium and basidiospores.<\/p>\n

    \"Figure<\/p>\n

    Figure 17. Coprinus X 400<\/p>\n<\/div>\n

    \"Figure<\/p>\n

    Figure 18. Coprinus X 1000 showing basidia and basidiospores<\/p>\n<\/div>\n

    Symbiotic Associations of Fungi and Other Organisms<\/h2>\n

    Lichens<\/h3>\n

    Lichens are structures made up of two different species:<\/p>\n

      \n
    1. a fungus<\/li>\n
    2. either a cyanobacterium or a green algae<\/li>\n<\/ol>\n

      The photosynthetic cells are contained within the middle layer.<\/p>\n

      The photosynthetic cells provide photosynthesis for the lichen. It was thought that the relationship was mutualistic because the fungus prevented the algal cells from desiccation. Recent evidence indicates that the photosynthetic cells may grow faster when separated from the fungus. Perhaps the fungus is parasitizing the photosynthetic cells.<\/p>\n

      Reproduction is asexual. Fragments are produced that contain fungal hyphae and photosynthetic cells.<\/p>\n

      Lichens derive most of their water and minerals from rainwater and air. This allows them to survive on bare rock, tree trunks, inhospitable places.<\/p>\n

      Observe the lichens on display. Some lichens have a crust-like appearance (crustose). Others have a shrublike (fruticose) or leaflike (foliose) appearance.<\/p>\n

      \"Figure<\/p>\n

      Figure 19. Lichens growing on a rock<\/p>\n<\/div>\n

      \"Figure<\/p>\n

      Figure 20. Lichens growing on a tree<\/p>\n<\/div>\n

      \"Figure<\/p>\n

      Figure 21. Lichens growing on a tree<\/p>\n<\/div>\n

      \"Figure<\/p>\n

      Figure 22. Lichen thallus (cross-section X 200)<\/p>\n<\/div>\n

      \"Figure<\/p>\n

      Figure 23. Lichen thallus X 400<\/p>\n<\/div>\n\n\t\t\t

      \n\t\t\t

      Candela Citations<\/h3>\n\t\t\t\t\t
      \n\t\t\t\t\t\t
      \n\t\t\t\t\t\t\t
      CC licensed content, Shared previously<\/div>