lecture 9 and 10 Flashcards
Which of the following diseases is NOT caused by a member of the picornavirus family?
Hepatitis A
Common cold
Influenza
Foot and Mouth Disease
Polio
influenza
Why is it unlikely that there will ever be an effective vaccine against the rhinovirus, the major cause of the common cold?
The immune system does not protect the nose.
There are over 100 different serotypes of rhinovirus.
Antibodies can not bind to the rhinovirus virion very well.
The immune system is not very effective at attacking rhinoviruses.
The common cold is too fast for the immune system to fight off.
There are over 100 different serotypes of rhinovirus.
Some picornaviruses have depressions, called “canyons”, on the surface of the virions. Which of the following describes the role that these depressions play?
They bind to the host cell receptor.
They adhere to the envelope.
They bind to antibodies.
They maintain the stability of the capsid.
They release the viral genome into the host cell.
They bind to the host cell receptor
The poliovirus protease cleaves the cellular eIF-4G protein. Why doesn’t this affect the virus?
The virus does not use cap-dependent translation.
The virus doesn’t use this protein as its host cell receptor.
The virus encodes the poly A tail as part of the genome.
The virus encodes its own RNA-dependent RNA polymerase.
The virus encodes its own version of this cellular protein.
The virus does not use cap-dependent translation.
Since translation of mRNAs in eukaryotic cells produces only a single polypeptide, how do picornaviruses produce multiple proteins from their RNA genome?
They produce multiple subgenomic mRNAs.
They use multiple IRES regions to translate multiple open reading frames.
They cleave a single polypeptide into individual proteins.
Their genome consists of a multicistronic mRNA.
They have internal translation start sites in their genome.
They cleave a single polypeptide into individual proteins.
Picornaviruses cause cytopathic effects in infected host cells by doing all of the following EXCEPT:
Inhibiting host cell mRNA synthesis.
Degrading cellular DNA.
Lysis of plasma membrane
Inhibiting intracellular transport from the ER to the Golgi.
Inhibiting cap-dependent translation of mRNAs.
Inhibiting cap-dependent translation of mRNAs.
Picornaviruses cause cytopathic effects in infected host cells by doing all of the following EXCEPT:
Inhibiting host cell mRNA synthesis.
Degrading cellular DNA.
Lysis of plasma membrane
Inhibiting intracellular transport from the ER to the Golgi.
Inhibiting cap-dependent translation of mRNAs.
Degrading cellular DNA.
Circulating vaccine-derived polio strains are more often associated with:
Locations where vaccine coverage is uneven
Populations with access to good sanitation
Areas having effective monitoring of polio strains
People living in rural, sparsely populated areas
Individuals previously vaccinated with the Salk vaccine
Areas having effective monitoring of polio strains
The Sabin attenuated polio vaccine is no longer used in vaccinations programs in the U.S. because….?
The vaccination method was painful and complex
The level of vaccine-derived polio cases was considered too high
The attenuated strain did not mimic the normal infection route
Only circulating antibodies were induced
It was not effective in eliminating wild type polio strains
The level of vaccine-derived polio cases was considered too high
Circulating vaccine-derived polio strains are more often associated with:
Locations where vaccine coverage is uneven
Populations with access to good sanitation
Areas having effective monitoring of polio strains
People living in rural, sparsely populated areas
Individuals previously vaccinated with the Salk vaccine
Locations where vaccine coverage is uneven
Which of the following describes the primary mechanism of transmission of the flavivirus Hepatitis C?
Contaminated food and water
Animal bites
Aerosols
Contaminated blood transfusions
Mosquito bites
Contaminated blood transfusions
In the mature flavivirus virion, the fusion peptide on the E protein is buried in the dimer interface. Which of the following conditions causes the fusion peptide to become exposed?
Uptake of the virion via receptor mediated endocytosis.
Interaction with the sialic acid residues on the surface of the cell.
Binding to the host cell receptor on the surface of the cell
Drop in pH in the endosome.
Binding to the host cell membrane.
Drop in pH in the endosome.
Which of the following describes the phenomenon of antibody-dependent enhancement?
Antibodies bound to a flavivirus particle allows entry into a cell via the Fc receptor.
Antibodies bound to a flavivirus particle allow it to be removed by the immune system.
The overproduction of antibodies during a flavivirus infection.
Antibodies bound to the host cell receptor make it unable to bind a flavivirus particle.
Antibodies bound to infected cells cause the immune system to kill them.
Antibodies bound to a flavivirus particle allows entry into a cell via the Fc receptor.
Which of the following statements comparing flaviviruses with picornaviruses is FALSE?
They both produce viral proteases to cleave the polyprotein.
They both have enveloped virions
They both use an IRES to initiation translation of the viral genome.
They both encode the structural proteins at the 5’ end of the genome.
They both produce their proteins from a single open-reading frame.
They both have enveloped virions
Flavivirus virions obtain their envelopes from the cellular membranes of which of the following organelles?
Golgi apparatus
Nucleus
Mitochondria
Endoplasmic Reticulum
Plasma membrane
Golgi apparatus
