Deck 14: Coronaviruses

Question 1

All of the following are diseases which can be caused by members of the coronavirus family EXCEPT:

A)Bronchitis
B)Hepatitis
C)Arthritis
D)Gastroenteritis
E)Encephalitis

Answer 1

C

Question 2

Which of the following statements about the proteinases from coronaviruses is FALSE?

A)They are encoded in the nonstructural region of the viral genome.
B)They are cysteine proteinases.
C)They are packaged into the virion.
D)They first cleave themselves out of the polyprotein.
E)They primarily cleave the non-structural polyprotein into mature proteins.

Answer 2

C

Question 3

Which of the following describes the structure of the coronavirus virion?

A)Naked helical capsid
B)Naked icosahedral capsid
C)Icosahedral nucleocapsid surrounded by an envelope
D)Helical nucleocapsid surrounded by an envelope
E)None of the above.

Answer 3

D

Question 4

How do coronavirus enveloped virions get released from the host cell?

A)The viral envelope fuses with the plasma membrane,releasing the virion.
B)They lyse open the host cell.
C)Virus containing vesicles fuse with the plasma membrane,releasing virions.
D)They bud from the surface of the host cell.
E)All of the above are mechanisms used by coronaviruses.

Question 5

The majority of known coronaviruses have been isolated from which of the following vertebrates?

A)Bats
B)Mice
C)Humans
D)Pigs
E)Birds

Question 6

Which of the following is an enzymatic function found in the nonstructural proteins of a coronavirus?

A)Methyltransferase
B)Helicase
C)RNA-dependent RNA polymerase
D)Ribonuclease
E)All of the above.

Question 7

Which of the following describes the mechanism used by coronaviruses to produce the ORF1b protein?

A)Read through a translational stop codon
B)Ribosomal frameshifting
C)RNA editing
D)Antitermination of transcription
E)Translation initiation at a downstream start codon

Question 8

Which of the following is a coronavirus that emerged as a serious human pathogen in Asia in 2003?

A)Ebola
B)SARS
C)Chikungunya
D)Coxsackie Virus
E)West Nile Virus

Question 9

The 5' two-thirds of the coronavirus genome contains which of the following?

A)IRES sequence
B)Non-structural protein coding sequences
C)Capsid protein coding sequences
D)Envelope protein coding sequences
E)Binding sites for the viral polymerase

Question 10

Which of the following have made it difficult to create a cDNA clone of the entire coronavirus genome that can be used in reverse genetics experiments?

A)The genome is too short to be cloned.
B)The genome contains regions that are resistant to cloning.
C)The viral RNA can not be converted to DNA.
D)The viral RNA from coronaviruses is not infectious.
E)Reverse genetics does not work with coronaviruses.

Question 11

What is unique about the structure of the subgenomic RNAs produced by the coronaviruses?

A)They each have their own IRES sequence.
B)They have a protein covalently attached to the 5' end.
C)They are synthesized from a full-length negative strand copy of the genome.
D)The first 60 to 100 nucleotides at the 5' end is the same.
E)They have a tRNA structure at their 3' end.

Question 12

The TRS sequence on the coronavirus genome is involved in which of the following processes?

A)Synthesis of the full length negative strand copy of the genome.
B)Transcription of the subgenomic negative strands.
C)Synthesis of the full-length positive strand genomes.
D)Packaging of the viral genome into the capsid.
E)Translation of the genome into protein.

Question 13

Even though some coronavirus virions have a hemagglutinin-esterase protein,they still cannot bind to sialic acid.

Question 14

Which of the following coronavirus proteins is responsible for virus entry and is the primary determinant of host range?

A)Spike (S)protein
B)Envelope (E)protein
C)Membrane (M)protein
D)Hemagglutinin-Esterase (HE)protein
E)Nucleocapsid (N)protein

Question 15

Coronaviruses have the longest RNA genome of any known virus.

Question 16

The membrane proteins of coronaviruses are glycosylated in which of the following cellular compartments?

A)Cytoplasm
B)Endosome
C)Lysosome
D)Smooth ER
E)Golgi apparatus

Question 17

Enveloped virus-like particles can be formed in cells when only the M and E protein from a coronavirus are expressed.What does this indicate?

A)That these proteins can not associate with the nucleocapsid.
B)That these proteins can not associate with each other.
C)That these proteins are sufficient for assembly and budding of virions.
D)That these proteins require HE and S for virion formation.
E)All of the above are correct.

Question 18

The complex RNA structure called a pseudoknot in the genome of coronaviruses is involved in which of the following processes?

A)Translation initiation of the nonstructural proteins.
B)Translation initiation of the structural proteins.
C)Replication of the positive strange genomes.
D)Packaging of the genome into the capsid.
E)Ribosomal frameshifting from ORF1a to ORF1b.

Question 19

Which of the following processes does NOT contribute to the evolution of coronaviruses?

A)Genome Reassortment
B)Random point mutations
C)Error rate of the RNA-dependent RNA polymerase
D)Selection in new host species
E)RNA-RNA recombination

Question 20

Which of the following might explain the potentially low barrier to species jumping seen in coronaviruses?

A)The large size of the RNA genome.
B)The modular nature of the Spike glycoprotein.
C)The ability of one virus to bind to multiple host cell receptors.
D)The ability of the virus to reassort its genome segments.
E)The high number of envelope glycoproteins found on the virion.

Question 21

Describe the two alternative hypotheses for how a bat coronavirus evolved to infect humans and cause the SARS epidemic in 2003.Which one does the evidence appear to support?

Question 22

The negative-strand RNA templates account for over 10% of the RNA molecules found in a coronavirus infected cell.

Question 23

The subgenomic mRNAs in the coronaviruses are synthesized from subgenomic negative-strand templates.

Question 24

If the Spike protein from some coronaviruses is incorporated into the plasma membrane of host cells,it can cause cell fusion and the formation of syncytia.

Question 25

Unlike the other positive-strand RNA viruses that have simpler genomes,coronaviruses produce a nested set of sub-genomic mRNAs,each of which is translated into a single protein.Explain why the virus needs to produce so many subgenomic mRNAs.