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Fungi
Recyclers, Pathogens, Parasites, and Plant Partners
- Fungi are more closely related to animals than plants
- Key features:
- · Absorptive heterotrophy
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- Some get energy from dead organic matter
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- Saprobes
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- Major decomposers on Earth
- Some get energy from other living organisms
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- Parasites
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- Some kill and consume prey
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- Predators
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- Some form partnerships with other organisms
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- Mutualists
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- · Chitin in cell walls
- The clades of fungi exhibit differences in their lifecycles
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Highly reduced, parasitic fungi
- Charateristics:
- · Approximately 1,500 species described
- · Unicellular
- · Obligate intracellular parasites
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The only fungi with flagella
- Characteristics:
- · Approximately 1,000 species
- · Unicellular and multicellular
- · Most are saprobic, but some parasitic and mutualistic
- Reproduction: flagellated spores and gametes (not in other groups)
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Zygospore Fungi (Zygomycota)
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Only one diploid cell in their entire life cycle
- Characteristics:
- · Approximately 1,060 species
- · Some unicellular (“yeasts”)
- “Yeast”
- -does not refer to a single taxonomic group
- -single celled species in the Zygomycota, Ascomycota, and Basidiomycota
- · Others multicellular
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- Multicellular “body” is the mycelium made of tubular filaments called hyphae
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- Hyphae may be:
- · Septate – divided by septa
- · Coenocytic – lack septa
- Zygospore fungi are coenocytic
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- · Mostly saprobic, but some parasitic and mutualistic
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- Black bread mold – a saprobic zygospore fungi
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Arbuscular Mycorrhizal Fungi
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No direct evidence of sexual reproduction
- Characteristics:
- · < 200 species
- · Multicellular with coenocytic hyphae
- · Mostly mutualistic (with plants)
- Mycorrhiza = “fungus-root”
- Mutualism:
- · Plant supplies carbohydrates
- · Fungi supplies water and nutrients
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Sexual reproductive structure is the ascus
- Characteristics:
- · 64,000 species
- · Unicellular (yeasts; approximately 800 species) {Saccharomyces cerevisiae : Baker’s or Brewer’s yeast is a sac fungi}
- · Multicellular with segmented hyphae (hyphae have septa)
- · Saprobes, parasites, and mutualists
- Saprobe: Penicillium
- Parasite: chestnut blight
- Mutualist: lichens
- Associations of fungi with photosynthetic cyanobacteria and/or unicellular algae
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Club Fungi (Basiddiomycota)
- Sexual reproductive structure is the basidium
- Characteristics:
- · 30,000 species
- · Unicellular (yeasts)
- · Multicellular with segmented hyphae
- · Saprobes, parasites, and mutualists
- Saprobe: bracket fungi
- Parasites: ex., some of the most damaging plant pathogens
- Mutualist: mycorrhizae
- Another type of “fungus root” (Do not grow inside the root cell)
- Club fungi produce some of the most spectacular fruiting structures or mushrooms
- Some are edible
- A basidiomycete may be the largest organism by area in the world
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