microcpara lab

• Fungi


  • Chemoheterotrophic
  • Have cell walls typically composed of chitin
  • Do not perform photosynthesis
  • Lack chlorophyll
  • Related to animals
• The Significance of Fungi

  • Decompose dead organisms and recycle their nutrients
  • Help plants absorb water and minerals
  • Used for food, in religious ceremonies, and in manufacture of foods and beverages
  • Produce antibiotics and other drugs
  • Serve as important research tools
  • 30% cause diseases of plants, animals, and humans
  • Can spoil fruit, pickles, jams, and jellies
• Molds


  Fungi form in multicellular called hyphae
• Yeast


  Fungi form in unicellular
• Mushroom or toadstool


  Spore-bearing fruiting body or fungi
• Hypha forms


  • Septate hypha
  • Non-septate hypha
  • Mycelium (branched hyphae)
• Yeast forms


  Pseudomycelium (yeast cells cling together)
• Nutrition of Fungi


  • Acquire nutrients by absorption
  • Most are saprobes
  • Some trap and kill microscopic soil-dwelling nematodes
  • Haustoria allow some fungi to derive nutrients from living plants and animals
  • Most fungi are aerobic
  • Many yeasts are facultative anaerobes
• Reproduction of Fungi


  • Asexual reproduction involving mitosis and cytokinesis
  • Sexual reproduction
• Asexual reproduction of Fungi

  1. Budding and asexual spore formation

  2. Yeasts bud in manner similar to prokaryotic budding

  3. Some yeasts produce long filament called a pseudohypha

  4. Filamentous fungi produce lightweight spores that disperse over large distances
• Sexual reproduction of Fungi

  1. Fungal mating types designated as "+" and "-"

  2. Four basic steps
• Classification of Fungi


  • Division Zygomycota
  • Division Ascomycota
  • Division Basidiomycota
  • Deuteromycetes
• Division Zygomycota


  • 1100 known species
  • Most are saprobes
  • Others are obligate parasites of insects and other fungi
  • Reproduce asexually via sporangiospores
• Microsporidia


  • Once classified as protozoa
  • More similar to zygomycetes by genetic analysis
  • Obligate intracellular parasites
  • Spread as small, resistant spores
  • Nosema parasitic on insects
  • Used as biological control agent for grasshoppers
  • Several genera cause disease in immunocompromised patients
• Division Ascomycota


  • 32,000 known species
  • Ascomycetes form ascospores in sacs called asci
  • Also reproduce by conidiospores
  • Includes most of the fungi that spoil food
  • Some infect plants and humans
  • Many are beneficial
  • Penicillium
  • Saccharomyces
• Division Basidiomycota


  • 22,000 known species
  • Mushrooms and other fruiting bodies of basidiomycetes called basidiocarps
  • Basidiomycetes affect humans in several ways
  • Most are decomposers that return nutrients to the soil
  • Many mushrooms produce toxins or hallucinatory chemicals
  • Some cause expensive crop damage
• Deuteromycetes


  • Heterogeneous collection of fungi with unknown sexual stages
  • Most deuteromycetes belong to the division Ascomycota based on rRNA analysis
• Lichens


  • Partnerships between fungi and photosynthetic microbes
  • Fungus provides nutrients, water, and protection
  • Photosynthetic microbe provides carbohydrates and oxygen
  • Abundant throughout the world
  • Grow in almost every habitat
  • Occur in three basic shapes: Foliose, crustose, fruticose
  • Create soil from weathered rocks
  • Some lichens provide nitrogen in nutrient-poor environments
  • Eaten by many animals
• sporangiospore


  lollipop
• Zygospore


  Couple
• Conidiospore


  walis
• yeast


  sesame seeds
• Zygomycota = Coenocytic (aseptate) = Rhizopus
• Ascomycota / Ascospores = septate; some associated with cyanobacte-ria or green algae to form lichens = Claviceps, Neuro-spora, Penicillium , Saccharomyces, Tuber
• Basidiomycota/Basidiospores = Septate =Agaricus, Amanita, Cryptococcus