What are Protozoa?

1
What are Protozoa?
proto first zoa animals
single-celled eukaryotic organisms
2
Combined Protein Consensus Tree
From S.L. Baldauf (1999) Am. Nat. 154S178
3
What are Protozoa?
proto first zoa plant/animal?

• Unicellular eukaryotes
• protozoa
• algae
• yeast/fungi
• slime molds

4
mm micron 10-6 meters (1/1000 mm)
5
Protozoan Life Styles

• absorb solutes (osmotrophy)
• ingest particulates (phagotrophy)
• predation on bacteria or other protozoa
• pinocytosis (fluid uptake)
• photosynthetic (autotrophy)
• combinations (heterotrophy)

free-living vs. symbiosis
6
(No Transcript)
7
Protozoan Reproduction
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
Protozoan Diversity

• gt200,000 named species
• 10,000 parasites
• 20 human pathogens

16
Protozoan Motility
17
Protozoan Taxonomy

• confused, controversial and constantly changing
• originally based on motility (light microscope)
• ultrastructural (electron microscope) criteria
  used since 1960s
• molecular data can help with evolutionary
  relationships
• monophyletic groups
• descended from common ancestor
• kinetoplastids, apicomplexa, ciliates
• polyphyletic groups
• multiple ancestors
• amebas and flagellates

Genus species
18
What are Protozoa?

• unicellular eukaryote
• ?
• ?
• ?

• extremely diverse

But not simple!
19
(No Transcript)