Ch 28 Protists (NOT DONE) Flashcards
Characteristics of protists
1) Eukaryotes
2) Unicellular
Is “protist” a good monophyletic group?
No
It is polyphyletic
Protist
Anything that is not a fungus, plant, or animal
How many phyla are included as protists?
30 to 40
Xenophyophores
Deep sea protists
What are the larger free-living single cells?
Xenophyophores
How large are xenophyophores?
Over 10 cm long
Endosymbiosis
The process in which a unicellular organism engulfs another cell, which becomes an endosymbiont and then organelle in the host cells
Mitochondria evolved via what?
Endosymbiosis of an aerobic prokaryote
Plastids evolved via what?
Endosymbiosis of a photosynthetic prokaryote
What is now thought to have occurred repeatedly in the evolution of eukaryotes?
Endosymbiosis
Supergroup Excavata
Share a similar cytoskeleton and some have an “excavated” feeding groove on the side of the body
Supergroup Excavata includes:
1) Diplomands
2) Parabasalids
3) Euglenozoans
Diplomands have (1)___ that do not function in (2)___ ___
1) Mitochondria
2) Aerobic metabolism
Diplomands have two equal-sized (1)___ and mulitple (2)___
1) Nuclei
2) Flagella
Giardia lamblia
A parastie of the human digestive tract
A diplomand
How is Giardia lamblia acquired?
By drinking from infected streams, etc.
Parabasalids have (1)___ that generate some energy (2)___
1) Hydrogenosomes
2) Anaerobically
Hydrogenosomes
Reduced mitochondria
Trichomonas vaginalis
Commonly infects the human urinary and reproductive tracts
A parabasalid
Euglenozoans includes what three things?
1) Predatory heterotrophs
2) Photosynthetic autotrophs
3) Parasites
Main defining characteristic of Eugleonzoans
A spiral or crystallin tod inside the flagella
Two groups included in Euglenozoans:
1) Kinetoplastids
2) Euglenids
Trypanosoma brucie
Infects humans and cattle
A kinetoplastid (Euglenozoan)
What does Trypanosoma brucie cause?
African sleeping sickness caused by invasion of the central nervous system
How is Trypanosoma brucie transmitted from host to host?
By tsetse flies
The genome of Trypanosoma brucie codes for what?
Variable surface glycoproteins (VSG’s)
Variable surface glycoproteins (VSG’s)
Are expressed sequentially to help the parasite evade the host’s immune system
Leishmania
Can cause cutaneous (skin) or internal infections
A kinetoplastid (Euglenozoan)
Leishmania is carried by what?
Sandflies
Leishmania occurs where?
All continents except Australia and Antarctica
Euglena
A Euglenozoan
A mixotroph
