single celled eukaryotes Flashcards
protists
single celled eukaryotes
for the flagellates; the flagella are mostly
anterior
for the flagellates, how many flagella per cell
usually 2 or more
flagellates mitochondria is
highly modified
difference between flagella and cilia
cilia; short, lots of them, fast beating, rotating cell, short
flagellum: long, threadlike, 1-10, wave-like, undulating beat, slow beat
what are the 2 subgroups of flagellates that we considered
diplomonadida and euglenozoa
diplomonads mitochondria
DON’T HAVE ONE! possess mitosomes, but not used for ATP generation, they lack plastids
diplomonadida characteristics
-long lineage
-flagella
-most anaerobic (life in low oxygen)
-most symbiotic and many are parasites
important member of flagellates in diplomonadida subgroup
giardia
-human and animal intestinal parasite
-resistant cysts contaminate water supplies, cysts can survive in cold water/ ice
-diarrhea in cats, dogs, caged birds
“eyes” are nuclei, around 10 flagella
-trophozoite stage (diagnostic stage)
-cyst stage (infective stage)
euglenozoa symbiosis?
many free living, some parasitic
what is a type of parasite euglenozoid and what are their characteristics
kinetoplastids, named this bevause mitochondrian has large circular DNA body: kinetoplast
heterotrophs
flagellates
free living and parasitic species
what is an extremely important species of kinetoplastids (parasitic euglenozoids, flagellates)
trypansoma
responsible for nagana in animals and sleeping sickness in humans, chagas disease
how is sleeping sickness and nagana transmitted by tryansoma (an euglenozoid, flagellate)
tstetse fly
what are the groups of single celled eukaryotes we considered
1) the flagellates,
2) the ciliates, apicomplexans and others
3) plants and algae
4) amoebae
5) opisthokonts
what kind of parasite are aplicomplexans
intracellular
obligatory parasites
what are aplicomplexans named after
their apical complex that is used to invade cells
what is an apicomplexans special organelle that is like a chloroplast but lacks chlorophyll
apicoplast
how do apicomplexans move
no visible apparatus for locomotion, apical; complex secretes organelles and molecules from anterior end, flow along body= movement, glide, aslo reply on flow of medium for most movement
what is an important apicomplexan
babesia, invades red blood cells, babesiosis in cattle transmitted by cattle tick
what is tick fever in cattle caused by
2 species of babesia (apicomplexans) and 1 species of prokaryote
how many cows die during outbreak of tick fever in cattle
1 in 20, very expensive
what group do the apicomplexa and ciliata belong to
alveolata
apicomplexa and ciliata have no common morphological feature but do have molecular sequence identity
what environment do ciliata live
freshwater, also many in rumen
what is unique about ciliata nuclei
they have dual nucleus, macro and micro
what is a ciliata of veterinary importance
balantidium coli in pigs
describe the ciliata peculiar form of sexual reproduction
conjugation:
the macro nucelus is the functioning desktop where as the micronucleus is like the backup
two cells come together and dissolve into eachother, they then dissolve both of their macro nucleus and their micronucleus divides into 4, 3 of the 4 degrade and the one left over will copy itself (so there is 2), they then donate the copy to each other (still 2 each) and these 2 micronuclei will fuse together (one from own cell, one from other cell) and then each cell forms a new macro from the fused diploid micro, then the cells separate
ciliates in the rumen function
essential for digestion of plant material
how many ciliates in a rumen
many species and many many individuals, 50 billion
what does group 3 plants and algae include
land plants, red algae and green algae
what is red algae called
rodophyta
characteristics of red algae and uses
some multicellular, use chlorophyll and another pigment for photosynthesis so red,
used for:
sushi wraps
ice cream
agar
food stabilizers
what is green algae called
chlorophyta
characteristics of green algae
found in freshwater, marine and soil
comes in unicellular, colonial and multicellular forms
what are 2 importances of green algae
1) major autotrophs in marine environment
2) closest relatives to land plants
how do amoebae move
move by by cytoplasmic flow through projections called pseudopodia (-ium)
do amoebae have flagellum
no, they have pseudopodium
where are are amoebae found
soil, fresh water, marine
are amoebae heterotrophs or autotrophs
heterotrophs
other than movement what else are their pseudopodia used for
capturing prey
example of amoebae as an opportunistic parasite
Acanthamoeba and naegleria; both free living amoebae that can enter brain/ eye of host through freshwater contact
example of amoebae as obligate parasite
entamoeba; parasites of humans, starts by eating bacteria within human but then turns pathogenic and eats host cells, feeds on lining of GI tract and moves to liver
E. histolyica causes amoebic dysentery; 100 000 deaths/year
what are slime moulds
different sorts, some are amoebae
elements of both unicellular and multicellular life
originally thought to be fungi
why are opisthokonts named that
presence of single posterior flagellum in cell
unicellular have single flagellum
multicellular forms also have cells w single flagellum (ex sperm)
important group of opisthokonts
choanoflagellates
close relatives of animals
choanoflagellate characeristics
choano; collar
flagella produce water current for feeding, food is trapped in collar, many unicellular, some colonial
animals and fungi
multicellular group within the opisthokonta
important apicomplexans
babesia
coccidiosis
malaria
how do african tryanosomes cause disease in humans and animals (flagellate, euglenozoa, kinetoplastid)
They have variant surface glycoproteins (thick dense protein coat) their VSG is not recognized by the host and they can go undetected by immune system, they can periodically switch switch to another active VSG in order to stay undetected
they invade bloodstream and get into the CNS and cause coma and death
how do both kinetoplastid and giardia reproduce
binary fission
ciliates can undergo mitosis, but every so often will undergo conjugation, why?
their macronucleus is only functional for about 200 generations, then it needs to be broken down and a new one made
