MGY277 Final Exam Complete
Questions And Verified Answers
\Q\.intermediate hosts - ANSWER-✔asexual expansion of parasite
\Q\.definitive hosts - ANSWER-✔sexual reproduction of parasite
\Q\.what unique fungal cell pathways make active targets for anti-fungal drugs? - ANSWER-
✔ergosterol biosynthesis
\Q\.what is the intermediate host of Schistosoma? - ANSWER-✔snails
\Q\.what does the cell wall of a protozoa look like? - ANSWER-✔there is no cell wall
\Q\.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
\Q\.what pathogen is associated with contact lens wear? - ANSWER-✔Acanthamoeba keratitis
\Q\.why are Cryptosporidium so difficult to remove from a public water supply? - ANSWER-
✔they are resistant to chlorine
,\Q\.your pet mouse suddenly seems less afraid of you. what might it be infected with? -
ANSWER-✔Toxoplasma gondii
\Q\.what are common routes of helminth infections? - ANSWER-✔ingestion, through soil or
insect bites
\Q\.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
\Q\.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
\Q\.which of these infections is frequently associated with AIDS?
a. fungal/mycoses
b. helminth
c. protozoa - ANSWER-✔c. protozoa
\Q\.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)
\Q\.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
\Q\.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
\Q\.Cholera - ANSWER-✔- caused by gram negative Vibrio cholera
- colonizes in the small intestine mucous membrane
- causes stomach cramps, vomiting, diarrhea leading to severe loss of fluid and metabolic
acidosis which leads to circulatory collapse and death
- TCP operon hold the vibrio cells together and helps it to colonize (gene is encoded in
pathogenicity island)
- secretes an enterotoxin which is imported into cell through endocytosis and fuse into the
Golgi, the complex is then transfer to the ER and the A subunit separate from the rest. A subunit
activates host enzyme to generate cAMP and opens chlorine ion channel leading to water
leakage into cell and ions out of cell; mechanism interrupt ion flow in the epithelial cells of the
intestine. toxin is encoded in a phage genome; phage uses TCP operon as a receptor for the
entry of the bacteria cell
\Q\.Staph intoxication (toxic shock, scalded child) - ANSWER-✔- infect target via cut/wound
- gram positive bacteria
- release superantigen which can over stimulate T-cells, which results in massive production of
cytokines
- high level of cytokines can lead to fever, nausea, diarrhea, vomiting, organ failure, circulatory
system collapse and death
- causes autoimmunity suppression
Questions And Verified Answers
\Q\.intermediate hosts - ANSWER-✔asexual expansion of parasite
\Q\.definitive hosts - ANSWER-✔sexual reproduction of parasite
\Q\.what unique fungal cell pathways make active targets for anti-fungal drugs? - ANSWER-
✔ergosterol biosynthesis
\Q\.what is the intermediate host of Schistosoma? - ANSWER-✔snails
\Q\.what does the cell wall of a protozoa look like? - ANSWER-✔there is no cell wall
\Q\.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
\Q\.what pathogen is associated with contact lens wear? - ANSWER-✔Acanthamoeba keratitis
\Q\.why are Cryptosporidium so difficult to remove from a public water supply? - ANSWER-
✔they are resistant to chlorine
,\Q\.your pet mouse suddenly seems less afraid of you. what might it be infected with? -
ANSWER-✔Toxoplasma gondii
\Q\.what are common routes of helminth infections? - ANSWER-✔ingestion, through soil or
insect bites
\Q\.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
\Q\.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
\Q\.which of these infections is frequently associated with AIDS?
a. fungal/mycoses
b. helminth
c. protozoa - ANSWER-✔c. protozoa
\Q\.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)
\Q\.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
\Q\.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
\Q\.Cholera - ANSWER-✔- caused by gram negative Vibrio cholera
- colonizes in the small intestine mucous membrane
- causes stomach cramps, vomiting, diarrhea leading to severe loss of fluid and metabolic
acidosis which leads to circulatory collapse and death
- TCP operon hold the vibrio cells together and helps it to colonize (gene is encoded in
pathogenicity island)
- secretes an enterotoxin which is imported into cell through endocytosis and fuse into the
Golgi, the complex is then transfer to the ER and the A subunit separate from the rest. A subunit
activates host enzyme to generate cAMP and opens chlorine ion channel leading to water
leakage into cell and ions out of cell; mechanism interrupt ion flow in the epithelial cells of the
intestine. toxin is encoded in a phage genome; phage uses TCP operon as a receptor for the
entry of the bacteria cell
\Q\.Staph intoxication (toxic shock, scalded child) - ANSWER-✔- infect target via cut/wound
- gram positive bacteria
- release superantigen which can over stimulate T-cells, which results in massive production of
cytokines
- high level of cytokines can lead to fever, nausea, diarrhea, vomiting, organ failure, circulatory
system collapse and death
- causes autoimmunity suppression
