MGY277 - FINAL EXAM QUESTIONS WITH COMPLETE
ANSWERS 100% SOLVED
intermediate hosts - ANSWER asexual expansion of parasite
definitive hosts - ANSWER sexual reproduction of parasite
what unique fungal cell pathways make active targets for anti-fungal drugs? - ANSWER
ergosterol biosynthesis
what is the intermediate host of Schistosoma? - ANSWER snails
what does the cell wall of a protozoa look like? - ANSWER there is no cell wall
on the evolutionary tree, are protozoa more like trees or humans?
a. trees
b. humans
c. too diverse to make such a statement - ANSWER c. too diverse to make such a statement
what pathogen is associated with contact lens wear? - ANSWER Acanthamoeba keratitis
,why are Cryptosporidium so difficult to remove from a public water supply? - ANSWER they
are resistant to chlorine
your pet mouse suddenly seems less afraid of you. what might it be infected with? - ANSWER
Toxoplasma gondii
what are common routes of helminth infections? - ANSWER ingestion, through soil or insect
bites
your friend is visiting an area where Schistosoma is known to be endemic. what activities do
you tell your friend to avoid?
a. sleeping without a mosquito bed net
b. swimming in local ponds
c. drinking from the local city water supply
d. cats - ANSWER b. swimming in local ponds
and
c. drinking from the local city water supply
more likely to be b though
,which of the following are NOT part of the Ascaris lifecycle?
a. infecting snails
b. entering the lungs via the bloodstream
c. being shed in faeces
d. entering the host via ingestion of food contaminated with dirt - ANSWER a. infecting snails
life cycle:
ingested through contaminated soil, hatches in lungs, larvae matures in the small intestine
and exit through the feces
which of these infections is frequently associated with AIDS?
a. fungal/mycoses
b. helminth
c. protozoa - ANSWER c. protozoa
salmonella - ANSWER - distant variant of E.coli
- causes Salmonellosis + low acid resistance
- require ingestion of 10^6 bacteria to cause harm
- invade host tissues and produces toxins
, - uses type III secretion system to cause actin molecules to rearrange which induces
non-phagocytic cells to engulf the bacteria through endocytosis
- able to avoid macrophage ingestion and block macrophage fusion (using second TIIISS)
E.coli - ANSWER - integrates DNA into host (lysogeny)
- strain HS is commensal in humans
- strain O157:H7 is pathogenic (fever, diarrhea) and has LEE pathogenicity which gives type III
secretion system and effector proteins
- has actin pedestals
Shigella - ANSWER - closely related to variant of E.coli
- causes Shigellosis from 10-100 ingested Shigella bacteria
- more acid resistant than Salmonella
- invade host tissues and produce cytotoxins
- takes advantage of M cells to cross intestinal barrier which is then engulfed by macrophages
but NOT destroyed, attaches to the base of intestinal epithelial cells and trigger the cells to
engulf them, then after being inside, the cells produce toxins which cause the host cell's actin
to polymerize; polymerization is able to direct transfer Shigella cells from host cells to an
adjacent epithelial cell
- infection mechanism allows it to avoid complement proteins, phagocytes and antibodies
- able to avoid phagocyte destruction by lysing the phagosome before its lysosome fusion
- Shiga toxin inactivates the eukaryotic ribosome 60S subunit which blocks protein synthesis
and leads to hemolytic uremic syndrome
ANSWERS 100% SOLVED
intermediate hosts - ANSWER asexual expansion of parasite
definitive hosts - ANSWER sexual reproduction of parasite
what unique fungal cell pathways make active targets for anti-fungal drugs? - ANSWER
ergosterol biosynthesis
what is the intermediate host of Schistosoma? - ANSWER snails
what does the cell wall of a protozoa look like? - ANSWER there is no cell wall
on the evolutionary tree, are protozoa more like trees or humans?
a. trees
b. humans
c. too diverse to make such a statement - ANSWER c. too diverse to make such a statement
what pathogen is associated with contact lens wear? - ANSWER Acanthamoeba keratitis
,why are Cryptosporidium so difficult to remove from a public water supply? - ANSWER they
are resistant to chlorine
your pet mouse suddenly seems less afraid of you. what might it be infected with? - ANSWER
Toxoplasma gondii
what are common routes of helminth infections? - ANSWER ingestion, through soil or insect
bites
your friend is visiting an area where Schistosoma is known to be endemic. what activities do
you tell your friend to avoid?
a. sleeping without a mosquito bed net
b. swimming in local ponds
c. drinking from the local city water supply
d. cats - ANSWER b. swimming in local ponds
and
c. drinking from the local city water supply
more likely to be b though
,which of the following are NOT part of the Ascaris lifecycle?
a. infecting snails
b. entering the lungs via the bloodstream
c. being shed in faeces
d. entering the host via ingestion of food contaminated with dirt - ANSWER a. infecting snails
life cycle:
ingested through contaminated soil, hatches in lungs, larvae matures in the small intestine
and exit through the feces
which of these infections is frequently associated with AIDS?
a. fungal/mycoses
b. helminth
c. protozoa - ANSWER c. protozoa
salmonella - ANSWER - distant variant of E.coli
- causes Salmonellosis + low acid resistance
- require ingestion of 10^6 bacteria to cause harm
- invade host tissues and produces toxins
, - uses type III secretion system to cause actin molecules to rearrange which induces
non-phagocytic cells to engulf the bacteria through endocytosis
- able to avoid macrophage ingestion and block macrophage fusion (using second TIIISS)
E.coli - ANSWER - integrates DNA into host (lysogeny)
- strain HS is commensal in humans
- strain O157:H7 is pathogenic (fever, diarrhea) and has LEE pathogenicity which gives type III
secretion system and effector proteins
- has actin pedestals
Shigella - ANSWER - closely related to variant of E.coli
- causes Shigellosis from 10-100 ingested Shigella bacteria
- more acid resistant than Salmonella
- invade host tissues and produce cytotoxins
- takes advantage of M cells to cross intestinal barrier which is then engulfed by macrophages
but NOT destroyed, attaches to the base of intestinal epithelial cells and trigger the cells to
engulf them, then after being inside, the cells produce toxins which cause the host cell's actin
to polymerize; polymerization is able to direct transfer Shigella cells from host cells to an
adjacent epithelial cell
- infection mechanism allows it to avoid complement proteins, phagocytes and antibodies
- able to avoid phagocyte destruction by lysing the phagosome before its lysosome fusion
- Shiga toxin inactivates the eukaryotic ribosome 60S subunit which blocks protein synthesis
and leads to hemolytic uremic syndrome
