Biology 121

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Biology 121
2011-12-07 21:25:27
Chapter 22

Chapter 22
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  1. What are the key features of fungi?
    • - bodies consist of slender threads
    • - obtain their nutrients from other organisms
    • - propagate by spores
    • - reproduce both sexually and asexually
    • - multicellular
    • - Cells are surrounded by cell walls composed of chitin, a nitrogen-containing polysaccharide
  2. The body of almost all fungi is ________.
  3. _______ is an interwoven mass of one-cell-thick, threadlike filaments called hyphae.
  4. In fungi, a threadlike structure that consists of elongated cells.
  5. __________ are haploid reproductive cells capable of developing into an adult fungus.
    -Usually produced in large numbers.
    -Dispersed by animals or air currents.
  6. Occurs when environmental contitions are stable, a haploid mycelium produces asexual spores by mitosis.
    Asexual reproduction
  7. Occurs when environmental conditions change,two haploid hyphae of different mating types fuse,- A diploid zygote forms after two haploid nuclei fuse- Haploid sexual spores form after the zygote undergoies meiosis- Sexual spores from new mycelia genetically different from the original hyphae.
    Sexual reproduction
  8. What are the four major groups of Fungi?
    • - Chytridiomycota
    • - Zygomycota
    • - Basidiomycota
    • - Ascomycota
  9. Unlike most types of fungi, _____ live in water. They also have swimming spores that propel itself through water by means of a single flagellum located on one end of the spore.
  10. __________can reproduce by forming diploid spores.
    -Sporangia form haploid spores during asexual reproduction.
    -Diploid zygospores form after sexual reproduction.
    -Soft fruit rot and black bread mold caused by species in the Rhizopus genus.
    (Zygomycetes) Zygote fungi
  11. _________ form spores in a saclike case.
    -Specialized hyphae form asexual spores.
    -Spore containing saclike cases called asci form after sexual reproduction.
    Sac fungi or Ascomycetes
  12. _______ produce Club-Shaped Reproductive Structures.
    -Club-shaped diploid basidia form after sexual reproduction.
    -Basidia produce haploid basidiospores by meiosis. -Basidia and basidiospores form in fruiting bodies like mushrooms, puffballs, and shelf fungi.
    -Fairy rings develop as hyphae grow outwards in a circular pattern from a basidiospore that germinated.
    Club Fungi or Basidiomycetes
  13. Symbiotic relationships with Mycorrhizae...
    • - Partnerships between fungi and plant roots
    • - Fungus increases the availability of minerals, organic nutrients, and water for the plant
    • - Plant produces sugars absorbed by the fungus.
    • - Plants with mycorrhizae grow better than plants without
  14. How does fungi affect humans?
    • - Fungi attack plants that are important to people.
    • - Fungi cause human diseases
    • - Fungi can produce toxins
    • - Many antibiotics are derived from fungi
    • - Fungi make important contributions to gastronomy
    • - Fungi plays a crucial ecological role
  15. Fungi attacks what plants that are important to people?
    • *Corn- by corn smut (though in Mexico, corn smut is a delicacy and known as the Mexican truffle)
    • * Wheat and apple rusts

    • - Trees damaged by fungi
    • *American elms
    • *Chestnuts

    • - Wood rot and textile damage
    • - Fungi that benefit agriculture - fungal pathogens used to control insect pests
  16. Fungi can cause what human diseases?
    • - Skin diseases - athlete's foot, ringworm
    • - Vaginal yeast infections
    • - Internal diseases - valley fever, histoplasmosis
  17. Fungi can produce what kinds of toxins?
    • - Aflatoxins- produced by molds in the genus Aspergillus
    • - Ergot- fungal toxin associated with infected rye
  18. What atibiotics are derived from fungi?
    • - Penicillin- was the first antibiotic discovered.
    • - Cyclosporin - an immunosuppressive drug imortant for transplaant patients.
  19. Fungi make important contributions to Gastronomy.....
    • - Direct - morels, truffles, mushrooms.
    • - Indirect - cheeses flavored by molds
    • - Yeasts' contributions
    • *Wine and beer are made using yeasts' alcoholic fermentation
    • *Yeasts make bread rise CO2 produced during alcoholic fermentation
  20. Fungi play a crucial ecological role....
    • - Digestive activities release nutrients from dead plant and animal bodies.
    • - Soil enriched and nutrients used by plants.
  21. Evolutionary connections.......
    • - Truffles (rare ascomycetes)
    • *Astronomical prices
    • *How they're found
    • - The shotgun approach to spore dispersal
    • - Nematode entrapment
  22. Nematode entrapment?
    - Arthrobotrys, the nematode (roundworm) strangler, traps its prey in a nooselike modified hypha that swells when the inside of the loop is contacted.