2. Protists, What are they?
Protists are defined by what they are
NOT…
Eukaryotes that are not plants, animals,
or fungi
Scientists believe they were the “1st
eukaryotic organisms”
Most are unicellular (algae exception)
Many are “aquatic”
Very diverse kingdom
4. Animal-like Protist
Heterotrophic organisms
Distinguished by how they move :
1) flagella: long “tail-like” structure
2) pseudopods: “false feet”
extensions of cytoplasm
3) cilia: tiny “hair-like” structures
beat in unison
4) some immobile
5. Sarcodines
Animallike protists use
pseudopods for
feeding and moving
Ex) Amoeba
Food
6. Ciliates
Animallike protists use
cilia for feeding and
movement
Ex) Paramecium
7. Zooflagellates
Animallike protists swim
using flagella
Trypanosoma protist
spread by the bite of tsetse
fly causes African Sleeping
Sickness
Giardia can contaminate
water and cause digestive
problems
Trichonympha lives in
mutualistic relationship
with termites
8. Sporozoans
Animallike protists that do not move on their own and
are parasitic
Plasmodium sporozoan causes malaria
Sporozoan parasite is carried by female Anopheles
mosquito
9. Plasmodium Life Cycle
Mosquito bites human
parasite injected
• Parasites invade liver
reproduce and develop
• Liver cells burst and
parasites move red
blood cells
• RBC burst person
experiences anemia,
fever, chills, may result in
death
• Parasites may then move
into other RBC or are
picked up by mosquito
and transferred to
another person
10. Plantlike Protists: Unicellular
Algae
Photoautotrophs- contain chlorophyll
and carry out photosynthesis
Often called “phytoplankton”- small
photosynthetic organisms near the surface
of ocean
Phytoplankton carries out
photosynthesis releasing oxygen into
the atmosphere
Phytoplankton important food source for
many “filter feeders”
12. Diatoms
Produce thin, delicate cell walls made of
silicon
Used in toothpaste, paints on license
plates, dynamite
13. Plantlike Protists: Algae
Red Algae-
mostly multicellular
algae contains special
pigments that allows it
to live deep areas of
water
Brown Algae-
all multicellular and
most are found in
marine environments
(ex: Kelp)
14. Plantlike Protists: Algae
Green Algae- some are unicellular, some form
colonies, few are multicellular
Volvox
Chlamydomona
s
Sea Lettuce
15. Humans and Algae
• Humans understand many beneficial uses of
algae:
1) Used to make nutrient agar
2) Used as ingredient in ice cream, pudding,
salad dressing, syrups
3) Food source – humans and other animals
4) Releases oxygen from photosynthesis
• Algae causes harm in “algal blooms” –
depletes water of nutrients and oxygen
16. Funguslike Protists
Heterotrophic protists that absorb nutrients, but
lack cell walls with chitin
Ex) Slime molds- found near moist, rotting logs
and composts
Ex) Water molds – can be parasitic and cause
“ick” in fish