Transcript 11Ch28Protists2008

Kingdom: Protists
Domain Eukarya
Domain
Bacteria
AP Biology
Domain
Archaea
Domain
Eukarya
2007-2008
Common ancestor
General characteristics
 Classification criteria
eukaryotes
 not animal, plant or fungi

That’s more of
what they’re not
& not
what they are!
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Great Diversity
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Problems with Protist Classification
 Too Diverse!


doesn’t reflect any evolutionary relationship
amongst all kingdom members
paraphyletic
Something’s
not right here!
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Theory of Endosymbiosis
internal
membrane
system
aerobic
bacterium
Eukaryotic cell with
mitochondrion
Ancestral eukaryotic cell
chloroplast
mitochondrion
photosynthetic
bacterium
AP Biology
Eukaryotic cell with chloroplasts
Paramecium &
symbiont Chlorella
Protist Diversity
 The full spectrum of modes of life
from unicellular to multicellular
 autotrophic to heterotrophic
 asexual to sexual reproduction
 pathogenic to beneficial
 sessile to mobile

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Mobility
 How Protists move
flagellum
 cilia
 pseudopod

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Protist Diversity
 Animal-like Protists

heterotrophs, predators
 Amoeba
 Paramecium
 Stentor
Amoeba ingesting a Paramecium
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Paramecium with food
vacuoles stained red
Protist Diversity
 Plant-like Protists

autotrophs, photosynthesis
 Euglena
 algae
 diatoms
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Protist Diversity
 Parasitic & pathogenic Protists
malaria
 Giardia
 trypanosomes

Plasmodium
Giardia
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Trypanosoma
Protist Diversity
 Beneficial & necessary Protists

phytoplankton
 small algae + diatoms
 much of the world’s photosynthesis
 produces ~90% of atmospheric oxygen

zooplankton
 heterotrophic protists + animals
 key ecological role at base of
marine food web
Mmmmmm!
Sounds like breakfast!
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Any
Questions??
AP Biology
2007-2008