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13 Cards in this Set
- Front
- Back
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Heterotrophs were once classified with fungi, but they're not anymore. Why not?
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This group's cell walls don't have chitin so they're not funji
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the three phyla of "molds" are:
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Phylum Oomycota (oomycetes)
Phylum Acrasiomycota (cellular slime molds) Phylum Myxomycota (plasmodial slime molds) |
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characteristics of Oomycota: (4)
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1. parasites or saprobes
2. cellulose (no chitin) 3. hyphae 4. asexual/sexual repro. |
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what is a saprobe?
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organisms that feed on dead organic matter
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What is hyphae?
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filamentous structures (threadlike cells)
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Phylum Oomycota has a unique reproduction cycle. How are they sexual organisms? (via what? what happens to zygote)
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via gametic meiosis; zygota becomes thickwalled oospore.
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How is the Phylum Oomycota asexual? (what to they make, how)
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make asexual spores called mitospores by mitosis.
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What are swimming mitospores called? What do they have that is unique?
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zoospores. two unequal flagella pointing in opposite directions
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What is the importance of Phylum Oomycota?
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some cause disease of plants or fish (potato blight, downy mildew). Phytophthora is cause of Irish potato famine
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Phylum Acrasiomycota has two characteristics?
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1. closely related to amoebas
2. found in freshwater and on rotting vegetation |
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Phylum Acrasiomycota has a 4 step life cycle:
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1. free living amoebas
2. lack of food, congregates into a multicellular slug 3. slug goes to light, then becomes sorocarp 4. sorocarp has sex repro. and macrocysts (2n) form and they go through zygotic meiosis |
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Plylum Myxomycota has 5 characteristics:
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1. feeding phase is plasmodium
2. plasmodium has a cytoplasmic streaming 3. its an "organic ooze that flows around and ingests matter 4. can make diploid/haploid spores = cysts 5. sporangium forms when there's not enough food |
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what is a plasmodium?
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a nonwalled, multinucleated mass
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