Transcript Protists
Kingdom Protista
Protists
most diverse kingdom
all eukaryotic
mostly unicellular aquatic organisms
asexual reproduction generally by binary fission
3 different groups
1. plant-like
2. animal-like
3. fungi-like
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1. Plant-like Protists: Algae
all autotrophs
contain chlorophyll
have cell walls
2 major groups
a) unicellular algae
phytoplankton
b)multicellular algae
seaweed
diatoms
brown algae
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Plant-like Protists: Algae
a) unicellular algae
very important because:
begin every aquatic food chain
2. produce 67% of atmospheric O2
3. overpopulation causes algal blooms which can
cause:
i) dead algae decomposed by saprophytes
consume large amounts of O2 – none left for
fish
swamp produced
ii) produce toxins which kill fish
can also be harmful to humans
ex. red tide
1.
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Plant-like Protists:Seaweed
b) multicellular algae (seaweed)
no real tissues i.e. colonies
food source for fish and humans
cell walls of red algae used to
make:
i. agar
ii. gel caps
iii. cosmetics
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Volvox
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2.Fungus-like Protists (Slime Moulds)
multicellular body (like giant
amoeba) called a plasmodium
roll over forest floor feeding
on dead organic matter
move very slowly
(few mm/day)
reproduce asexually with
spores (like fungi) in fruiting
bodies
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3. Animal-like Protists
all heterotrophs
classified by how they move
a) pseudopods:
move with cytoplasmic projections called
pseudopods (false feet)
ex. amoeba
• some pathogenic
•i.e. amoebic dysentery
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Animal-like Protists
b) flagellates
move with long whip-like
flagella
some parasitic pathogens
ex. African sleeping sickness
Giardia lamblia
(beaver fever)
trypanosome
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Animal-like Protists
c) ciliates
move with cilia (short
hair-like projections)
that can cover cell
ex. paramecium
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Animal-like Protists
d) sporozoa
reproduce by asexually
by spores
have no means of
locomotion
many parasites, which
depend on host body
fluids to move
ex. Malaria
RBC
anopheles
mosquito
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Paramecium Structure
cilia
contractile vacuole
cytoplasm
micronucleus
macronucleus
oral groove
gullet
food vacuole forming
anal pore
food vacuole
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Paramecium
spiral movement
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Paramecium Reproduction
Binary fission
(asexual reproduction)
same 2 organisms
(genetically different )
Conjugation
•
•
(sexual reproduction)
have two nuclei
exchange micronucleus with
another paramecium
2 new organisms
(genetically identically )
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Amoeba Structure
contractile vacuole
endoplasm
food vacuole
pseudopod
ectoplasm
nucleus
Note: contractile vacuole
cytoplasm
•collects all the H2O that
diffuses in by osmosis
•contracts & pumps H2O out
to stop amoeba from bursting
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Amoeba Feeding
phagocytosis
pseudopod
food
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pseudopod
surrounds
food
food enters
a food
vacuole
enzymes
break down
food in
vacuole
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Amoeba Reproduction
Binary Fission (asexual)
one amoeba divides into 2 identical amoebas
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