Virology Exam 2

For ss (+) RNA viruses which is the first enzyme used for copying the genome? -reverse transcriptase -The RNA-dependent RNA polymerase (RdRp) -DNA-dependent DNA polymerase -Integrase

What is a key difference between the (+) ss RNA genome of poliovirus and mRNA? -Poliovirus genomes have the presence of a protein cap (VPg) on the 5' end. -Poliovirus genomes are very short. -Poliovirus genomes can be transcribed in the nucleus. -Traditional mRNA must go through additional modifications before it can be transcribed into proteins.

Which of the following viruses does not target immune cells during infection? -Zika virus -Norovirus -HIV -Mumps virus -Dengue virus

Humans are dead end hosts for Zika virus? True False

What contributes to the cyclical nature of Norovirus outbreaks? -Loss of herd immunity -Changes in seasons -Viral evolution and the emergence of new viral strains -None of the answers are correct

Which viral enzyme is directly involved in integrating the DNA made from the HIV genome into the host chromosome? -Reverse Transcriptase -RNA-depedent RNA polymerase (RdRp) -Protease -Integrase

In which way is the retrovirus HIV, unlike other single stranded, positive sense (+), RNA viruses. -Retrovirus RNA gets transcribed in the cytoplasm -Retroviruses encode an RNA transcriptase (RT) to convert their RNA to DNA -Retroviruses are smaller than all other ss(+) RNA viruses -Retroviruses are enveloped while other ss(+) RNA viruses are not

Which detection method is best for early detection of HIV? -RNA/DNA tests that detect viral genomes -They are all equally good for early detection of the virus. -Antibody tests that detect the immune response made to the virus -Antibody-Antigen tests that detect the virus in the blood

What is the most common mode of transmission for HIV? -Blood Transfusions -Sexual contact or intercourse -IV drug use -Transfer from mother to child

Which enzyme make DNA from the HIV RNA? -Integrase -Protease -RNA-dependent RNA polymerase (RdRp) -Reverse Transcriptase

What type of cytopathic effect would you expect to see when culturing mumps virus? -Cellular swelling and foamy degeneration -focal degeneration -fusion bodies -syncytia formation

Which ss(-) RNA virus has a 100% mortality rate? -Mumps virus -Ebola Virus -Influenza virus -Rabies virus

Which of the following is a unique characteristic of Influenza replication in comparison to other RNA viruses? -Influenza is taken up by endocytosis. -Influenza RNA goes into the nucleus for transcription -Influenza mRNAs can't be directly copied to make full length genome. -Influenza RNA remains in the cytoplasm for transcription.

Of the choices below, how does translation of VSV differ from translation of Poliovirus? -Translation for VSV occurs in the cytoplasm, while translation for Poliovirus occurs in the nucleus. -VSV translates each protein sequence individually while Poliovirus translates one long polyprotein that is ultimately cleaved by viral proteases. -VSV uses viral enzymes to cleave its polyprotein, which poliovirus uses cellular enzymes. -Translation of proteins for VSV and Poliovirus are not different.

What enzyme comes packaged in the Influenza viral capsid, attached to the (-) RNA segments? -Reverse Transcriptase -DNA polymerase -Integrase -RNA polymerase

Although animal parvoviruses and human noroviruses are genetically distinct and possess different replication strategies, there are several characteristics of infection that are common among these viruses. Which of the following are commonalities between parvovirus infection in dogs/cats and norovirus infection in humans? Check all that apply. -A low infectious dose -Bloody diarrhea as a symptom of disease. -Infection can be prevented through the use of a commercially available vaccine. -Very high quantities of virus are shed in the stool.

Why must dsRNA viruses package an RNA-dependent RNA polymerase (RdRp) inside their viral capsid? -Because all RNA viruses package an RdRp. -Because the (+) of RNA in their genome cannot function as mRNA. -Because the RdRp converts the RNA to DNA so it can be translated by host ribosomes. -dsRNA viruses don't actually package an RdRp.

Which of the following are important feature of ssDNA replication? Check all that apply. -The ability of the virus to replicate in the cytoplasm. -The use of host cellular enzymes in DNA replication. -The presence of hairpin structures at the ends of the genome. -The large number of viral proteins encoded by the ssDNA genome.

Inverted terminal repeats form which important structures of linear ssDNA molecules? -Inverted terminal repeats are not a feature of ssDNA genomes. -Cleavage site to initiate genome replicaiton -Hairpin structures -Priming site to allow for DNA polymerase binding

One day you find yourself sick with both diarrhea and vomiting. Since you've taken Virology, you know that you are likely infected with either Norovirus or Rotavirus. Which aspect of your illness or symptoms would give a good indication of which virus you were infected with? -Children are immunized with vaccines against Norovirus, so I must be infected with Rotavirus. -My symptoms only lasted 24 hours, so it's most likely a Norovirus infection. -I'm an adult so I most likely have a Rotavirus infection. -It's impossible to make an educated guess about which virus I have based on symptoms or pattern of infection.