Contractile vacuole action

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• Contractile vacuole action

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• Amoeboid movement

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• See it!

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• Chapter 31 Fungi

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Fungi

• Heterotrophic by absorption (exoenzymes)
• Decomposers (saprobes), parasites, mutualistic
  symbionts (lichens)
• Hyphae body filaments
  septate (cross walls)
  coenocytic (no cross walls)
• Mycelium network of hyphae
• Chitin cell walls (polysaccharide)

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LE 31-2
Reproductive structure
Hyphae
Spore-producing structures
20 µm
Mycelium
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Fungus Life Cycle

• Most have 3 distinct phases
• Haploid (n)
• Heterokaryotic (n n) (think of Sordaria)
• Diploid (2n)

Asexual phases (n spores, n clones)Sexual
Phases (n spores, w/ genetic variety) Plasmogamy
(cytoplamic fusion) Dikaryotic (n
n) Karyogamy (nuclei fusion) Diploid
(2n) Meiosis (spores n)
Bread Mold Life cycle
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Fungi Diversity, I

• Phy Chytridiomycota aquatic fungi chytrids
  lineage closest to protists
  (flagella)
• Phy Zygomycota Rhizopus (food mold)
  mycorrhizae mutualistic with plant roots
  zygosporangia resistant structure (freezing
  and drying)

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Fungi Diversity, II

• Phy. Ascomycota sac fungi
  yeasts, truffles, morels, Sordaria
  asci sexual spores
  conidia asexual spores
• Phy. Basidiomycota club fungus
  mushrooms, puffballs, shelf fungus, rusts
  basidiocarps produce sexual spores

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Specialized Lifestyles, I

• Molds only the asexual
  stage (asexual spores) Penicillium (antibiotic,
  cheese)
• Yeasts unicellular, asexual
  budding Saccharomyces (bread, alcohol)

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Specialized Lifestyles, II

• Lichens
  symbiotic association held in a hyphae mesh
  alga provides food, fungus
  provides physical environment
  pioneer organisms air
  pollution detection
• Mycorrhizae root
  and fungi mutualism found in 95 of
  vascular plants
  exchange of organic minerals increases
  absorptive surface of roots

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