Protozoan evolution and development Flashcards
describe protozoa?
eukaryotic, unicellular, single celled
how did eukaryotic cells form?
1) infolding that ingested an aerobic heterotrophic prokaryote (became mitochondria)
2) membrane infolding taking prokaryotic chromosome into an early membrane bound nucleus
what is a chimera? is there heritability?
grafting/transplatation of tissues
NO heritability
what is a composite? is there heritability?
different tissue types in ONE organism through merging of genetically distinct cells eg protozoa
there IS heritability
what is the evidence for protozoa being composites?
some protozoa have chloroplasts AND flagella
why is Giardia an anomaly?
how can this be explained?
- no mitochondria or peroxisomes
- genome doesn’t encode myosin
EXPLANATION: Giardia diverged from euk PRIOR to mitochondria endosymbiosis
related genes occur because of INDEPENDENT ANALOGOUS evolution
which 4 broad categories are included in protozoa?
amoeba, ciliates, flagellates, apicomplexans
what is the function of amaebae Pseudopodia?
movement and feeding
what is the function of amaebae plasmasol
hardens and liquefies for TRACTION
how is food obtained for amoeba?
CHEMOTAXIS(detect food)
- use plasmasol to form pseudopodia
- ingest food by attacking via OXIDATIVE BURST
what are the different names for flagella?
fimbria, mastigonemata
describe the Flagellates contain? nutrition where are they found food storage?
- many cont chloroplasts
- saprotrophic/phagotrophic
- common in freshwater
- store food as fat or paramylon
MAY HAVE - more than 1 flagella
- eye spot
- PELLICLE (allows cell to retain shape/rigidity)
what is a protozoa with flagella called?
what is their flagella made of?
UNDULIPODIA
made of TUBULIN
what is the function of the cytosome?
ingests particles as a feeding mechanism
how do phytoflagellates obtain nutrition?
attack external cell layer of marine animals—> removing cytoplasmic content —> can cause severe damage
describe the structure of ciliates
- cilia linked by tubles that form a KINETOSOME
- kinetosome arranged to rows (max particle uptake)—> KINETIES
what is the only ciliate that causes disease in humans?
Balantidium coli
what is the function of the micronuclei?
controls cell division & DNA replication
what is the function of the macronuclei?
controls all other aspects bar cell division & DNA replication
who does Balantidium coli affect?
what is the pathogenesis of ciliate Balantidium coli?
- immunocompromised
- causes gastroenteritis
- produces extrasomes—> improves ability to feed—>attach to small org—> suck out cytoplasm
which organisms does Balantidium coli affect?
humans (if immunocompromised)
and poultry
who does apicomplexa infect?
invertebrates and vertebrates
what diseases does apicomplexa cause?
malaria, coccidiosis, toxoplasmosis
how do apicomplexa obtain nutrition?
what do they lack?
mostly saprozoic
PARASITIC
lack flagella or psuedopods
how do apicomplexa respire and excrete?
simple diffusion via cell membrane
what can endobiotic bacteria cause?
eg
live inside body and cause damage due to size (eg Giardia attached to intestial wall)
endocytobiotic means what?
invades RBC, lives here
Cryptosporidiosis causes what?
O requirements?
acute infection
facultative
