Which is not a component of innate immunity?
A.
Skin
B.
Inflammation
C.
Fever
D.
Antibody
Phagocytes were first discovered and named by
A. Pasteur.
B. Koch.
C. Lister.
D. Metchnikoff.
Would ID50 and LD50 necessarily be the same for a given virus? Why or why not?
A. Yes, because the number of viruses that infect 50 of a test population should also kill 50 of that test population.
B. No, because a virus may be highly infectious (very low ID50 value) but only marginally lethal (very high LD50 value). A prime example of this is the rhinovirus (common cold virus).
C.
No, because very few viruses are lethal, yet many are highly infectious. The two values should ALWAYS be different.
D. Yes, because what we're actually describing here is infection/killing of individual CELLS, not of entire organisms. If a cell is infected, it will always be killed.
Why is it virtually impossible to stamp out a disease caused by a zoonotic virus?
A. You'd have to drive the vector organism extinct to do so.
B. Many vector organisms have multiple stages of their life cycle that can carry a zoonotic virus, which complicates controlling the vector-borne transmission.
C. Many viruses transmitted in this manner may utilize more than one vector organism.
D.
Many zoonotic viruses may be able to reside in more than one host organism, complicating control measures.
E. All of the above are correct.
Would you expect the number of virions to be the same if you measured them by the plaque assay or by counting using the electron microscope? Why?
A. Yes-both methods measure the total number of virus particles in a solution.
B. No-the plaque assay only measures viable virus particles, while the electron microscope cannot distinguish between defective and viable virus.
C. No-you cannot count virus particles by using a plaque assay. You can only get a relative difference in quantity from one preparation of virus particles to another with this method.
D. Yes-only fully functioning viruses will be released from a host cell, so the quantified number of virus particles in a plaque assay should be identical to the number of free virus particles counted by electron microscopy within a given preparation.
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