Ch. 28: Protists

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Ch. 28: Protists
2014-04-18 11:30:30
mew mustard protists

made by mew for mustard ;3
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  1. protists
    • mostly unicellular eukaryotes: simplest eukaryotes
    • 0.5-2 micrometers in diameter (small as many prokaryotes)
    • Some are more closely related to plants, fungi, or animals than they are to other protists.
  2. Unicellular protists carry out the same functions as multicellular organisms by using __ instead of multicellular organs.
    subcellular organelles
  3. Compared to other eukaryotes, protists are nutritionally __.
    diverse: meaning they can be photoautotrophs, heterotrophs, or mixotrophs (combination of the 2)
  4. How do protists reproduce?
    highly varied: some sexually, some asexually
  5. What gave rise to enormous diversity of protists that exist today?
    • endosymbiosis
    • First eukaryotes acquired mitochondria by engulfing an aerobic prokaryote.
    • An additional endosymbiont is a photosyntetic cynobacterium that evolved into plastids.
    • Plastids gave rise to 2 lineages of photosynthetic protists, or algae
  6. DNA of plastid genes in red and green algae closely resemble the DNA of
  7. During eukaryotic evolution, red and green algae underwent __.
    secondary endosymbiosis: They were ingested in the food vacuoles of heterotrophic eukaryotes and became endosymbionts themselves.
  8. Excavata
    • include diplomonads, parabasalids, and euglenozoans
    • Molecular data indicate they are monophyletic. (only a hypothesis)
  9. Diplomonads and Parasabalids both
    • lack plastids
    • have modified/reduced mitochondria
    • found in anaerobic environments
    • Many are parasites
  10. The modified mitochondria in Diplomonads are called __ and differ from regular mitochondria, because __.
    mitosomes; They lack functional electron transport from carbs and other organic molecules. Instead, they get energy from anaerobic chemical pathways.
  11. structure of Diplomonads
    • 2 equal-sized nuclei
    • multiple flagella
  12. Giardia intestinalis (lamblia) is
    a diplomonad (parasite) which inhabits the intestines of mammals
  13. The modified mitochondria in Parabasalids are called __ and they generate energy by __.
    hydrogenosomes; releasing hydrogen gas as a byproduct (anaerobically)
  14. Trichomonas vaginalis is
    a parabasalid; sexually transmitted parasite that travels along the mucus-coated lining of the human reproductive and urinary tract by moving its flagella and by undulating part of its plasma membrane
  15. Euglenozoans belong to a diverse clade that includes
    predatory heterotrophs, photosynthetic autotrophs, and parasites
  16. The main morphological feature that distinguishes euglenozoans is
    the presence of a rod with either a spiral or crystalline structure inside each of their flagella
  17. Kinetoplastids
    • a group of Euglenozoans
    • have a single, large mitochondrion that contains a organized mass of DNA called a kinetoplast
    • include species that feed on prokaryotes in freshwater, marine, and moist terrestrial ecosystems
    • also species that parasitize animals, plants, and other protists
  18. Trypanosomes are
    a genus of kinetoplastids (Euglenozoan) which infect humans and cause sleeping sickness, also causes Chagas' disease
  19. Euglenid
    • a group of Euglenozoans
    • has a pocket at one end from which 1 or 2 flagella emerge
    • mixotrophs