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Eukaryotes w/modified
mitochondria
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mitosomes & hydrogenosomes
surrounded by 2 membranes
no organelle DNA; genes in nucleus
similar protein targeting to organelles
mostly anaerobic habitats
– Giardia intestinalis (mitosomes)
– Trichomonas vaginalis (hydrogenosomes)
Euglenozoans
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flagella structure unique
heterotrophs & autotrophs
eg Euglena
complex unicells
two types of movement
farm ponds, high nutrients
– red carotenoid pigments
Haptophytes aka
Coccolithophorids
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unicellular flagellates
autotrophs, impt in C cycle
CaCO3 scales = coccoliths
cool Earth 3 ways:
remove CO2 if sink
reflect light
promote cloud formation
– release S compounds--> aerosols
– some bacteria can prevent
Alveolates
• membrane cavities = alveoli
• 3 very different types of unicells
1. Dinoflagellates
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dino = whirl
2 flagella
plates in alveoli
heterotrophs, autotrophs
fw & marine
Photosynthetic dinoflagellate symbionts of coral
= “zooxanthellae”
toxic dinoflagellates
• Blooms--human pollution (N, P)
– Eg big hog farm waste, NC
• Red tides (pigment from Dino)
– Shellfish poisoning
• example: Pfisteria piscicida
– carnivorous, w/feeding tube
– neurotoxin: stuns fish, eats them
2. Apicomplexans
• apex has complex of host-penetrating
organelles
• eg. Plasmodium--malaria
– 2 hosts: mosquitos, humans
– Resistant to drugs
– plastids (no pigments)--vulnerable?
3. Ciliates
• Among most complex of cells
• Cilia for locomotion (9+2 like flagella)
Example: Vorticella
cilia around top of cup
Sessile (attached) stalk contracts like slinky
Stramenopiles
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stramen “straw” pile “hair
unicellular & multicellular
autotrophs & heterotrophs
3 examples:
1. oomycetes
• heterotrophs, decomposers
• Phytophthora infestans
David Schmale
– late blight of potato
– great potato famine
• Phytophthora ramorum
– “sudden oak death” kills many trees
2. diatoms
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autotrophs, brown pigments
plankton, ubiquitous
glass-like walls of silica
diatomaceous earth
test microscope resolution
make oil—biofuels?
3. brown algae
• autotrophs,
brown pigments
• incl. kelps—largest,
most complex protists
• some kelps grow
60 m in 1 season
• keystone species—
others depend on
complex structure of kelp blade
blade
stipe
holdfast
example of
endosymbiosis involving
a stramenopile
chlplsts of stramenopile,
Vaucheria
ingested by sea slug Elysia
lives 10 months, no food
gene from nucleus of alga
found in nucleus of Elysia
PNAS Nov 18, 2008
105: 17867-17871