Kingdom Protista
•
•
•
•
•
Eukaryotes
Most with one cell (Unicellular)
Some with many cells (Multicellular): seaweed
Autotrophs or Heterotrophs
Protists contains organisms that do not fit into
the other eukaryotic kingdoms
• Protists evolved from prokaryotes (bacteria)
• Protista can be:
Animal-like, Plant-like, Fungus-like
Movement in Protista
1. Flagella: long, whip-like projection
Most have just 1 or 2 flagella
2. Cilia: Short, hair-like projections.
Too many cilia to count
Paramecium caudatum
3. Pseudopods: Temporary projections of
the cytoplasm. Change shape constantly
Amoeba proteus
Reproduction
1. Binary Fission:
Split into 2 identical
cells
2. Conjugation:
Exchange
pieces of DNA.
Then split in 2.
Increase genetic
diversity
1. Animal-like Protista
• All heterotrophic (like animals). Need to consume
other organisms
Trypanosoma:
parasite blood
Vorticella:
cilia, freshwater
Trichonympha:
Intestine of termites
Trychonympha breaks
down cellulose in wood.
Paramecium:
Freshwater,
Figure 20-5 Acilia,
Ciliate
Section 20-2 unicellular
Trichocysts
Lysosomes
Oral groove
Gullet
Anal pore
Contractile vacuole
Micronucleus
Macronucleus
Food vacuoles
Cilia
2. Plant-like Protista = Algae
• All autotrophic, like plants. Photosynthesis
• Have chlorophyll inside chloroplasts.
Volvox: freshwater
Diatoms: aquatic with a shell
- produce most O2 on Earth
Green algae (seaweed)
Marine, multicellular
Euglena: freshwater,
Unicellular, flagellum
Plankton: very small floating organisms in
freshwater and marine environments.
Plankton = Phytoplankton + Zooplankton
1. Zooplankton: heterotrophic organisms
2. Phytoplankton: autotrophic organisms –photosynthesis
Phytoplankton
produce most
of the oxygen
on Earth!!
Phytoplankton from Space
3. Fungus-like Protista
• All heterotrophs – Decomposers: Absorb
nutrients from dead or decaying organic matter
Slime mold on mulch
Phytophthora infestans:
Potato blight – destroyed potato
crops in Ireland in 1844-1851