ch 5 Flashcards
What is an example of a diseases in humans caused by eukaryotes
protozoal disease malaria
protist parasite giardia causes diarrheal illness
why does microbiology include parasites
identification depends on observation of microscopic adult worms or eggs
why does the word protist not a formal taxonomic term
the organisms do not have a shared evolutionary origin
describe algae
photosynthetic organisms that can be unicellular or multicellular
describe protozoa
non photosynthetic, motile, organisms that are always unicellular
what are plankton
microorganisms that drift or float in water, moved by currents
what are zooplankton
motile and non photosynthetic
what are phytoplankton
photosynthetic
what habitats to protozoans inhabit
aquatic and terrestrial, some are free living while others are parasitic in a host
what are trophozoites
beneficial symbionts that provide metabolic services, this is their name during feeding and growth cycle, they feed on small food sources such as bacteria
what can some protozoa develop into after trophozoites
encapsulated cyst stage, when environmental conditions are too harsh, the cyst is a protective wall
what is the process where a trophozoite becomes a cyst
encystment
what is excystment
when cyst are triggered to become active again
What is the life cycle of protozoa eimeria
unsporulated oocyst (non-infectious
sporulated oocyst (infectious)
oocyst enters gut when swallowed
oocyte releases sporocysts
sporozoites invade gut cells
trophozoite
schizogony (asexual reproduction)
schizont
merozoites released from schizont
male and female gametes
syngamy (sexual)
developing oocyst
oocyst shed in feces
how do protozoans reproduce
sexually
asexually
some bothh
how does asexual reproduction occur in protozoans
binary fission, budding or schizogony
what happens in schizogony
the nucleus of a cell divides multiple times before the cell divides into many smaller cells
what is the product of schizogony called
merozoites that are stored in structures known as schizonts
how do protozoan haploid gametes fuse
syngamy
how do protozoans exchange genetic material
conjugation that is different than conjugation in bacteria
what does protist conjugation refer to
a true form of eukaryotic sexual reproduction between two cells of different mating types
where is protist conjugation found
ciliates
what is the plasma membrane in a protozoan called
plasmalemma
what’s a pellicle
bands of proteinic the plasma membrane of some protozoans that adds rigidity
what is ectoplasm
OUTER LAYER with microfilaments of actin
distinct layers of cytoplasm under the membrane in some protist including protozoa
What is endoplasmm
the inner layer fluid region
what is cytostome
specialized structure for takininfoodthrough phagocytosis in some protozoans
what is cytoproct
specialized structure for the exocytosis of wastes
what does it mean if a protozoan is holozoic
it ingests whole food particles through phagocytosis
what does it mean if a protozoans saprozoic
it ingests small soluble foodmolecules
what are pseudopodia
“false feet” cytoplasmic extensions attached to the cell surface to some protists
how do pseudopodia work
they allow cytoplasm to flow into the extension, moving themselves forward
What are contractile vacuoles
organelles that can be used to move water out of the cell for osmotic regulation (salt water balance)
what is a polyphyletic group mena
they lack a shared evolutionary origin (protist)
what are the six supergroups of eukarya
Excavata
chromalveolata
rhizaria
archaeplastida
amoebozoa
opisthokonta
What are the subgroup of excavata
fornicata
parabasalids
euglenozoans
distinguishing features of fornicata
form cysts
pair of equal nuclei
no mitochondria
often parasitic
four free flagella
example of fornicata and disease
guardia lamlia
giardiasis
distinguishing features of parabasalids
no mitochondria
four free flagella
one attached flagellum
no cysts
parasitic or symbiotic
basal bodies
kinetoplastids
example and disease of parabasalids
trichomonas
trichomoniasis
distinguishing features of euglenozoans
photosynthetic or heterotrophic
flagella
examples of euglenozoans and disease
euglena/na
trypanosoma/ African sleeping sickness/ chugs disease
leishmania/leishmaniasis
subgroups of chromolveolata
dinoflagellates
apicomplexans
ciliates
oomycetes/peronosporomycetes
distinguishing features of dinoflagellates
cellulose theca
two dissimilar flagela
example and disease of dinoflagellates
gonyaulaz/red tides
alexandrium/ paralytic shellfish poising
pfiesteria/ harmful algae blooms
apixomplexans distinguishing features
intracellular parasite
apical organelles
example and clinical notes for apicomplexans
plasmodium/malaria
cryptosporidium/ cryptosporidiosis
theileria/babesiosis
toxoplasma/tozoplasmosis
ciliates distinguishing features
cilia
ciliates examples and clinical notes
balantidium/balantidiasis
paramecium
stentor
oocycetes/peronosporomycetes distinguishing features
“water molds”
generally diploid
cellulose cell walls
examples/ clinical notes of oomycetes/
phytophthora/ diseases in crops
What are the sub groups of rhizaria
foraminifera
radiolaria
cerocozoa
distinguishing features of foraminifera
amoeboid
threadlike pseudopodia
calcium carbonate shells
example of foraminifera
astrolonche
distinguishing features of radiolaria
amoeboid
thread like pseudopodia
silica shells
example of radiolaria
actinomma
distinguishing features of cercozoa
amoeboid
threadlike pseudopodia
complex shells
parasitic forms
examples of and clinical notes of cercoza
spongospora suberranea. powdery scab (potato disease)
plasmodiopora brassicae/ cabbache clubroot
subgroups of archaeplastida
red algae
chlorophytes
distinguishing features of red algae
chlorophyll a
phycoerythrin
phycocyanin
what does the supergroup amoebozoa include
protozoans that use amoeboid movement, actin microfilaments produce pseudopodia, into which the remainder of the protoplasm flows moving the organism
what is included in the entamoeba genus
commensal or parasitic species including e. histolytica
how is e. histolytic transmitted
by cysts in fecces and is the primary cause of amoebic dysentery
what does acanthamoeba cause
keratin’s (corneal inflammation
) and blindness
what is the brain eating amoeba
naegleria fowler a distant relative of the amoebozoa
what the eumycetozoa
a unusual group called slime molds which have been previously classified as animals, fungi and plants
what are the two types of slime molds
cellular slime molds and plasmodial slime molds
what do cellular slime molds exist as
individual amoeboid cells that periodically aggregate into a mobile slug, the aggregate then forms a fruiting body that produces haploid spores.
What do plasmodial slime molds exist as
large, multinucleate amoeboid cells that form reproductive stalks to produce spores that divide into gametes
Why is dictyostelium discoideum important
it is a cellular slime mold that has both single celled and multi celled life stages with cells showing some degree of differentiation in the multicelled form
What is the life cycle of cellular slime mold discoideum
- mature fruiting body generates spores>meiosis
- mature fruiting body releases spores
- spores germinate
- germination gives rise to amoeba, which divide to form more individual cells
- two amoebas fuse to form a zygote
- zygote grows and undergoes meiosis and multiple rounds of mitosis
- new haploid amoebas are released
- amoebas aggregate into a structure called a slug
- slug migrates at a rate of 2mm/hr
- migration stops and the aggregate forms a fruiting body at the of a stalk
plasmodial slime molds
1.Sporangia formation begins> meiosis
2. meiosis restores haploid condition
3. mature sporangium releases spores
4. spore germinates giving rise to cells that can convert between amoeboid and flagellated forms
5. germination gives rise to cells that can convert between amoeboid and flagellated forms
6. plasmogamy (fusion of cytoplasm)>fertilization
7.karyogamy (fusion of nuclei
what are apicomplexans
intra or extracellular parasites that have an apical complex at one end of the cell
what is the apical complex
a concentration organelles, vacuoles and microtubules that allow the parasite to enter host cells
describe the lifecycle of apicomplexans
they include infective sporozoite that undergoes schizogony to make many merozoites
what does the life cycle of apicoplexans depend on
transmission between multiple hosts
what does apicomplexan cryptospridium parvum cause
intestinal symptoms and can cause an epidemic diarrhea when the cysts contaminate drinking water
describe theileria micrti
transmitted by the tick, causes recurring fever and can be fatal and is becoming more common transfusion-transmitted pathogen
what is toxoplasma gondii
causes toxoplasmosis and can be transmitted from cat feces, unwashed fruit and veggies from undercooked meant
what are ciliates
a very diverse group within the chromalveolata characterized by cilia on cell surface
what are the cilia on ciliates used for
locomotion and feeding, some forms are nonmotile.
what is balantidium coli
the only parasitic ciliate that affects humans by causing intestinal illness but rarely causes serious issues except in immunocompromised.
What is paramecium
a mobile ciliate with a clearly visible cytostome and cytoproct.
what is stentor
a ciliate that uses its cilia for feeding and has micronucleus that is diploid, somatic and used for sexual reproduction by conjugation. they also have micronucleus derived from the micronucleus
what does the micronucleus become
polyploid and a reduced set of metabolic genes
how do ciliates reproduce
through conjugation
what is conjugation in ciliates
when two cells attach to each other, the diploid micronuclei in each cell undergo meiosis producing 8 haploid nuclei each, then all but one of the haploids and the macronuclei disintigrate
what happens to the remaining haploid micronuclei
it undergoes mitosis. the two cells then exchange one micronucleus each fusing with the remaining micronucleus to for a new genetically different diploid micornucleus
what is the end result of after division
4 micronuclei and two the four combine to form a new micronucleus that replicates DNA repeatedly, once it reaches its polyploid state the cells separate
what are oomycetes known as
watermolds
how do oomycetes differ from fungi
they have cell walls of cellulose and are generally diploid fungi are haploid
what is classified as an oomycetes
Phytophthora, the plant pathogen found in Irish potato famine
what’s included in excavata
primitive eukaryotes and parasites with limited metabolic abilities
describe excavata
they have complex cell shapes and structures often including a depression on the surface of the cell called an excavate
what subgroups are included in excavata
fornicata, parabasalia and euglenozoa
describe fornicata
they each mitochondria but have flagella
what does fornicata include
giardia lambda a widespread pathogen that causes diarrheal illness and can be spread through cysts from feces that contaminate water
describe parabasalia
frequent animal endosymbionts that live in the gut of animals like termites and cockroaches
they have basal bodies and modified mitochondria they have large complex cell structure with an undulating membrane and often have many flagella
what are trichomonads
a subgroup of parabasalia that includes trichomonads vaginalis an STD that causes issue in women
describe euglenozoa
common in the environment and include photosynthetic and non photosynthetic species, usually nonpathogenic
they have two flagella, a pellicle a stigma to sense light and chloroplasts
what is the pellicle of euglena made of
a series of protein bands surrounding the cell supporting the membrane and giving It shape
what are trypanosomes
parasitic pathogens in euglenozoa, African trypanosomiasis
tsetse fly stages
- tsetse fly bakes a blood meal and injects t bruce into blood stream
- T. Bruce multiples by binary fission in blood, lymph and spinal fluid
- fly takes a blood meal and injects t. bruce
- in the midst of the fly t. Bruce multiplies by binary fission
- t. Bruce transforms into an infectious stage
- Bruce enters salivary gland and multiplies.
