Deck 16: Filovirouses

Question 1

Budding of Ebola virus particles occurs at sites on the plasma membrane where which of the following is present?

A) Insertion of viral glycoproteins in the cell membrane.
B) Binding of the matrix protein with the cytoplasmic face of the cell membrane.
C) High concentrations of the host cell receptor.
D) Lower concentrations of phospholipids.
E) Where both glycoproteins and matrix protein are located.

Answer 1

E

Question 2

Inclusion bodies inside the cytoplasm of cells infected with Ebola virus are sites for which of the following processes?

A) Formation of viral envelopes.
B) Transcription of viral mRNAs.
C) Formation of viral nucleocapsids.
D) RNA editing of viral mRNAs.
E) Translation of viral proteins.

Answer 2

C

Question 3

Which of the following animals appears to be the reservoir for filovirus infections?

A) monkeys and primates
B) bats
C) racoons
D) domestic livestock
E) insects

Answer 3

B

Question 4

Which of the following proteins from Ebola virus resembles the matrix proteins from other RNA viruses?

A) VP24
B) VP40
C) VP30
D) L
E) VP35

Question 5

Marburg virus, a member of the filovirus family, has a higher mortality rate than either Ebola Zaire or Ebola Sudan.

Question 6

In wildtype Ebola virus infections, only 20% of the envelope glycoprotein contains the transmembrane domain.Which of the following mechanisms controls the production of this membrane form of the protein?

A) Alternative mRNA splicing
B) RNA editing
C) Ribosomal frameshifting
D) Reading through a stop codon
E) Proteolytic cleavage

Question 7

The virions of filoviruses are very different than the virions of other negative-strand RNA viruses.Which of the following describe this difference?

A) They are enveloped.
B) They are spherical.
C) They are narrow and elongated.
D) They don't contain a matrix protein.
E) They use a helical nucleocapsid.

Question 8

All of the following are similarities between filoviruses and paramyxoviruses EXCEPT….

A) They have enveloped virions.
B) They have negative-strand RNA genomes.
C) They have long thin virions.
D) They encode the nucleocapsid gene at the 3' end of the genome.
E) They encode the polymerase gene at the 5' end of the genome.

Question 9

Scientists produced a mutant Ebola virus that does not express any of the soluble form of the envelope glycoprotein (sGP)but can only express the membrane bound form (GP).Which of the following explains the results of infecting cells with this mutant?

A) It caused the cells to release more virus from the cell.
B) It resulted in virus particles with higher levels of GP.
C) It allowed the immune system to attack the virus.
D) It caused the virus to produce smaller plaques.
E) It reduced the cytopathic effect caused by the virus.

Question 10

Which of the following describes one of the important roles for the VP30 protein of Ebola virus?

A) Activation of mRNA synthesis.
B) Assembly of enveloped virions.
C) Packaging of the viral genomic RNA.
D) Binding to the host cell receptor.

Question 11

All of these proteins are associated with the nucleocapsids of Ebola virus EXCEPT which of the following?

A) NP - nucleoprotein
B) VP40 - matrix protein
C) L - viral RNA polymerase
D) VP35 - polymerase cofactor
E) VP30 - transcription activator

Question 12

Marburg virus is named after which of the following?

A) A river in Africa.
B) A country in Africa.
C) A town in Africa.
D) A town in Germany.
E) A country in Europe.

Question 13

Which of the following viruses has NOT been associated with lethal human disease?

A) Marburg
B) Ebola Sudan
C) Ebola Zaire
D) Ebola Reston
E) None of the above.

Question 14

All of the following describe a feature of the pathogenesis of the filoviruses EXCEPT…..

A) Induction of immunosuppression.
B) Infection of macrophages and monocytes.
C) Increased endothelial permeability.
D) Induction of cytokine release.
E) Problems with motor neurons and movement.

Question 15

The VP30 protein from Ebola virus activates synthesis of the NP mRNAs by doing which of the following?

A) Helps bring nucleotide triphosphates to the viral RNA polymerase.
B) Acts as a helicase to unwind the RNA template.
C) Counteracts the negative effects of a stem-loop at the 5' end of the mRNA.
D) Participates in the RNA editing process.
E) Causes the RNA polymerase to bind to the NP promoter more tightly.

Question 16

During an outbreak of Ebola virus, which of the following as NOT been shown to be a major source of transmission between individuals?

A) Preparation of bodies for burial.
B) Reuse of needles and syringes.
C) Sexual transmission.
D) Aerosol droplets.
E) Contact with contaminated blood.

Question 17

There is a concern that filoviruses could be used as agents of germ warfare.

Question 18

All of the following factors can affect the efficiency of transcription of the mRNAs in the Ebola virus EXCEPT….

A) Strength of the polymerase binding site.
B) Location of the gene in the genome.
C) RNA secondary structure at 3' end of gene.
D) RNA secondary structure in the intergenic region.
E) Presence of overlapping genes.

Question 19

The total number of recorded filovirus infections has not yet exceed 3000 cases.

Question 20

The intergenic regions in the Ebola virus genome contains signals for all of the following processes EXCEPT….

A) Transcription reinitaiton.
B) Trancription termination.
C) Polyadenylation.
D) RNA polymerase disengagement.
E) Genome replication.

Question 21

Most filoviruses have been isolated from monkeys taken from Asia.

Question 22

Labs that have Biosafety Level 2 are allowed to work with live infectious filoviruses.

Question 23

Filovirus infections are resistant to both treatment with interferon and ribavirin.

Question 24

Explain the system that has allowed scientists to produce infectious filoviruses using transfection of several plasmids into cells.

Question 25

The GP protein of Ebola virus is unusual from the glycoproteins from other negative-strand RNA viruses in two major ways.Describe these differences.