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Protists : eukaryotes , mostly unicellular

Protists and algae. Protists : eukaryotes , mostly unicellular. What kind of group? monophyletic paraphyletic polyphyletic. Biol 121, Fall 2010, Tom Buckley. 15 Sep 10. Protist diversity and phylogeny. Metabolic diversity. photoautotrophs chemoheterotrophs mixotrophs (both).

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Protists : eukaryotes , mostly unicellular

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  1. Protists and algae Protists: eukaryotes, mostly unicellular What kind of group? monophyletic paraphyletic polyphyletic Biol 121, Fall 2010, Tom Buckley 15 Sep 10

  2. Protist diversity and phylogeny Metabolic diversity photoautotrophs chemoheterotrophs mixotrophs (both)

  3. Protist diversity and phylogeny Fig 28.2 Protists w/ plastids: origin in two-stage endosymbiosis? plastids: chloroplasts (photosynthesis) amyloplasts (starch storage) chromoplasts (pigment storage)

  4. Fig 28.2 gram-negative

  5. - 2 2 3 - 4 3-4 4 observed expected # of membranes gram-negative 4 3-4

  6. Protist diversity and phylogeny photoautotrophs heterotrophs mixotrophs Metabolic diversity All arisen repeatedly in different lineages Q: Is photoautotrophyhomologous in photosynthetic protists?

  7. Protist diversity and phylogeny photoautotrophs heterotrophs mixotrophs Metabolic diversity All arisen repeatedly in different lineages Q: Is photoautotrophyhomologous in photosynthetic protists?

  8. Protist diversity and phylogeny photoautotrophs heterotrophs mixotrophs Metabolic diversity All arisen repeatedly in different lineages Q: Is photoautotrophyhomologous in photosynthetic protists?

  9. Protist diversity and phylogeny photoautotrophs heterotrophs mixotrophs Metabolic diversity All arisen repeatedly in different lineages Q: Is photoautotrophyhomologous in golden and brown algae?

  10. In SOME spp, two genes (DHFR & TS) have fused into a single gene Expt: Sequenced genes in protists & other spp blue: fused red: separate Q: -what is outgroup? -infer characters of ancestors Bacteria

  11. In SOME spp, two genes (DHFR & TS) have fused into a single gene Expt: Sequenced genes in protists & other spp blue: fused red: separate Q: Predict whether the genes are fused in red algae Bacteria

  12. Protist diversity and phylogeny Key points Shared common names DO NOT imply monophyly "algae" "green algae" "seaweeds" & "kelp" "molds" including fungi "amoebas"

  13. Oomycete ("water mold") Postelsia ("sea palm") Porphyra ("seaweed")

  14. Protist diversity and phylogeny Other key points Fungi are closer to animals than to plants, water molds or slime molds Green algae are closer to plants than to other "algae"

  15. Ecology of protists Symbioses coral reefs: dinoflagellate + animal

  16. Ecology of protists Symbioses coral reefs: dinoflagellate + animal sudden oak death: Phytophthora ramorum(oomycete) + trees photo courtesy Jack Marshall, CDF

  17. Ecology of protists Primary production aquatic systems CO2 all other life CH2O reduction + electrons energy excess nutrients from fertiliser, wastewater, atmosphere algal blooms

  18. Laminaria (a brown alga) Alternation of generations mature Laminaria 'plant': sporophyte (diploid)

  19. Q: Which organisms in this diagram reduce CO2? (a) herbivorous plankton (b) protistan producers (c) bacteria (d) all of the above

  20. Exam I: next Mon, normal time bring 200-question scantron bring #2 pencil

  21. Review

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