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!
AP Biology
Great Diversity
AP Biology
Problems with Protist Classification
 Too Diverse!


doesn’t reflect any evolutionary relationship
amongst all kingdom members
paraphyletic
Something’s
not right here!
AP Biology
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

AP Biology
Protist Diversity
 Animal-like Protists

heterotrophs, predators
 Amoeba
 Paramecium
 Stentor
Amoeba ingesting a Paramecium
AP Biology
Paramecium with food
vacuoles stained red
Protist Diversity
 Plant-like Protists

autotrophs, photosynthesis
 Euglena
 algae
 diatoms
AP Biology
Protist Diversity
 Parasitic & pathogenic Protists
malaria
 Giardia
 trypanosomes

Plasmodium
Giardia
AP Biology
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!
AP Biology
Any
Questions??
AP Biology
2007-2008