biology chapter 22

  1. shared characteristics of fungi
    Fungi have threadlike bodies- they are made up of filaments ( hyphae)

    Cell walls made of chitin- a tough carb

    fungi are heterotrophic
  2. hyphae
    threadlike strands that make up fungi

    the cells of the hyphae are haploid, almost identical, and generally perform the same functions.

    hyphae form a tangled mass called mycelium

    in some fungi hyphae form rootlike structures called rhizoids
  3. obtaining nutrients
    fungi release enzymes that break down organic & inorganic matter into nutrients. They absorb the nutrients across their cell walls.

    fungi that absorb nutrients from dead organisms are called saprobes

    fungi that absorb nutrients from living hosts are called parasites.
  4. reproduction
    most fungi reproduce both sexually and asexually

    sexual reproduction- hyphae from one fungus fuse w/ hyphae from a fungus of the opposite mating type. The fused hyphae then make a reproductive structure & inside it nuclei from the two mates fuse = diploid nuclei which undergo meisos & produce haploid spores that are released. genetic diversity

    asexual reproduction. - specialized hyphae produce long stalks. @ the tip haploid spores are produced by mitosis. the fungi produce are genetically identical tot he parent. Allows for rapid spread.

    fungi that do not have an observed sexual stage are grouped together & called imperfect fungi.
  5. yeast & mold
    yeast- unicellular stage. usually reproduce by budding. under specific conditions can form multicellular hyphae & may reproduce sexually.

    mold- rapidly growing asexually reproducing stage. fungi that grow molds can be reproduce sexually or asexually.
  6. phyla of fungi
    chytrid fungi, zygote fungi, sac fungi, and club fungi.
  7. chytrid fungi
    a group of aquatic fungi that provide clues about the evolution of fungi

    most produce hyphae that form rhizoids

    mainly saprobes

    common parasites of aquarium fish & cause of amphibious decline
  8. zygote fungi
    • asexual is more common then sexual
    • spores carried by wind
    • species of rhizopus & other zygote fungi usually live in the soil & feed on decaying plants and animal matter.
  9. sac fungi
    phylum ascomycota

    dikaryotic - having two nuclei

    ususally reproduce asexually

    asexualy spores called conidia form by mitosis on specialized hyphae called conidiophores. conidia usually form in chains & are not covered, carried by wind & germinate
  10. club fungi
    characterized by basidium, a clublike sexual reproductive structure that produces spores.

    asexual is rare but occur in some rusts & smuts

    basidiocarps often form @ the outere edges of the large mycelial mats that club fungi produce. the mycelia grow out from a central starting point & form an expanding ring of hyphae. When the fungus reproduces sexually a ring of mushrooms appear.
  11. mutualistic relationships
    lichen- fungus & photosynthetic partner. phtotsynthetic organism provides carbs and the fungus provides protection and vitamins and minerals. survive extreme conditions

    mycorrhiza- fungi & roots of nearly all plants. hyphae transfer phosphorus & other minerals from soil to rot of the plant. the plant supplies carbs.
  12. dermatophytes
    fungi that infect the skin & nails.
  13. & industry

    • penicillin & cephalosporin
    • bread mold = cortisone
    • yeast= vaccine hepatitis b

    yeast= gashol a fuel alternative
  14. & ecosystem
    decomposes organic matter & absorbing & breaking down minerals from rock & soil.

    • lichen- prepares environments for other organisms
    • mycorrhizae- fungi absorb minerals from the soil & transfer them to plant roots.
  15. diseases
    because fungi grow within the tissue of their host, fungal infections can be difficult to cure.
Card Set
biology chapter 22
biology chapter 22