Virus Infection Quiz

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What characteristic of viruses contributes to their classification as non-living pathogens?

They are acellular (correct)

Their unique type of cells

Their ability to synthesize only some of their own components

Their extremely small size

How do viruses compare to both prokaryotic and eukaryotic cells?

They have similar metabolic processes

They lack genetic material

They lack proteins

They are generally smaller (correct)

In the scenario described, what type of infectious agent is indicated by the presence of RNA and protein but no carbohydrates or lipids?

Bacteria

Fungi

Viroids

Prions (correct)

What happens when a virus has an envelope?

It likely escapes its host cell by budding. Signup and view all the answers

In the given pictures, which one shows an icosahedral enveloped virus with spikes?

C Signup and view all the answers

What must all viruses do with their genome to produce , used by the host cell to produce ?

mRNA; proteins Signup and view all the answers

What do retroviruses use reverse transcriptase for?

Direct the production of double-stranded DNA from a single-stranded RNA genome Signup and view all the answers

If a newly-discovered double-stranded RNA virus has a unique enzyme synthesizing double-stranded RNA using an RNA template, what is likely true?

The virus must bring this enzyme into the host cell as animal cells do not have this capability. Signup and view all the answers

What contributes to viral genome evolution?

All of the above Signup and view all the answers

Which property is currently not used to classify viruses?

Host range of the virus Signup and view all the answers

Which event occurs during lysogenic replication of bacteriophage but not during lytic replication?

Integration of the phage DNA into the host cell DNA Signup and view all the answers

Which process during lytic replication of bacteriophage uses factors from the host cell?

Enzymes which transcribe and translate viral genes Signup and view all the answers

What is a characteristic of viruses that infect many different tissue types?

Broad tropism Signup and view all the answers

Which suffix denotes the 'family' level of classification for viruses?

-viridae Signup and view all the answers

In influenza virus, antigenic drift is characterized by what type of change in HA or NA spikes?

Spontaneous mutation leading to a minor change Signup and view all the answers

Which description does not match antigenic shift in the influenza virus?

Often results from spontaneous mutations Signup and view all the answers

Which viral family and its associated disease contains single-stranded+ RNA and reverse transcriptase?

Retroviridae (AIDS) Signup and view all the answers

All these are DNA viruses except which one?

Picornaviridae Signup and view all the answers

Which prion disease can be acquired by eating beef contaminated with a cattle prion?

Gerstmann-Straussler-Schienker syndrome Signup and view all the answers

How would the SARS-CoV2 virion structure be best described?

Naked icosahedral Signup and view all the answers

Which viral family contains single-stranded, positive-sense, nonsegmented RNA?

Filoviridae (Ebola) Signup and view all the answers

What is the human receptor protein for the SARS-CoV2 virus?

ACE-1 Signup and view all the answers

What type of viral infection is indicated by a patient presenting with fever, sore throat, and lesions that resolve but recur two months later?

Chronic persistent infection Signup and view all the answers

How do convalescent antibodies help treat patients with serious COVID-19 cases?

Have a placebo effect. Signup and view all the answers

Both viruses and prokaryotes reproduce by:

Budding Signup and view all the answers

Which term refers to the number of species that a specific virus can infect?

Host range Signup and view all the answers

In viral infections, what is the role of tropism?

Attachment to host cells Signup and view all the answers

How do naked viruses typically exit animal host cells?

By budding Signup and view all the answers

What occurs in persistent viral infections?

Viral integration into host cell DNA Signup and view all the answers

What is the primary difference between lytic and lysogenic bacteriophage replication?

Viral genome replication method Signup and view all the answers

Which procedure is used to detect both viral antigens and patient antibodies to a virus?

ELISA Signup and view all the answers

What do antiviral drugs primarily target in viral replication?

Viral nucleic acid production Signup and view all the answers

Why do new influenza vaccines need to be formulated annually?

To prevent antigenic drift Signup and view all the answers

What term describes major genetic reassortment in influenza viruses?

Provirus formation Signup and view all the answers

Which stage in viral infection involves the entrance of only the genome into a host cell?

Penetration Signup and view all the answers

What is the probable explanation when a plate is completely clear after incubation with a liquid suspension of bacteriophage and host bacteria?

The phage concentration was so high that all the host bacterial cells were killed. Signup and view all the answers

What does the plaque assay primarily determine?

Number of bacteriophage in a sample Signup and view all the answers

Which test works by detecting viral nucleic acid?

PCR Signup and view all the answers

What should be considered about using an agglutination test for HIV antibodies one week after a high-risk behavior?

One week may not be enough time for HIV antibodies to be detected. Signup and view all the answers

What is a major challenge in developing effective antiviral drugs with minimal side effects?

Viruses use the cell's own machinery and metabolism for replication. Signup and view all the answers

Prions are:

Misfolded proteins which can cause normal versions to also misfold. Signup and view all the answers

What is likely when a plate remains clear after incubation with a bacteriophage and host bacteria?

The bacteria are resistant to the bacteriophage. Signup and view all the answers

What is a key challenge in developing antiviral drugs?

Viruses mutate rapidly and can develop resistance to drugs. Signup and view all the answers

What is a limitation of using agglutination tests for viral infections?

They cannot differentiate between different strains of the same virus. Signup and view all the answers

What characterizes prions?

They misfold normal cellular proteins, leading to disease. Signup and view all the answers

What stage of animal virus replication may be blocked by a drug that binds with the viral spike?

Attachment Signup and view all the answers

Which part of viral replication is being blocked by the lack of a receptor in individuals with a genetic mutation?

HIV cannot attach to the host cell without the proper membrane receptor. Signup and view all the answers

What type of viral infection is demonstrated by a graph showing periods of active replication alternating with periods of dormancy?

Chronic persistent Signup and view all the answers

Which statement is not true about chronic persistent viral infections?

May involve integration of the virus into host cell DNA. Signup and view all the answers

What stage of viral replication involves penetration via endocytosis?

Penetration via membrane fusion Signup and view all the answers

In which stage of animal virus replication will not be different between naked and enveloped viruses?

Replication Signup and view all the answers

Which is not true about oncogenic viruses?

They are never RNA viruses. Signup and view all the answers

Which cancer type is not linked to a specific virus?

Skin cancer Signup and view all the answers

During a lysogenic infection, what happens to the phage DNA?

It remains as a prophage and is copied whenever the host cell replicates its genome Signup and view all the answers

What enzyme breaks down the host cell wall to release the bacteriophage?

Lysozyme Signup and view all the answers

How can an antiviral drug target the uncoating step of viral replication?

By preventing access to the virus nucleic acid Signup and view all the answers

Which drug family targets replication by preventing viral nucleic acids from being replicated or transcribed?

Nucleoside reverse transcriptase inhibitors (AZT) Signup and view all the answers

What is one characteristic shared by prions and misfolded proteins in neurodegenerative disorders?

They are infectious Signup and view all the answers

How does a prophage pass down to bacterium's daughter cells?

Through binary fission Signup and view all the answers

Which step of viral replication involves preventing mature virions from being put together?

Assembly Signup and view all the answers

Why are Alzheimer's, Parkinson's, and ALS considered 'prion-like' diseases according to recent medical research?

Because misfolded proteins can transmit dysfunction similar to prions Signup and view all the answers

What is the role of enfuviritide in combating viral replication?

Preventing attachment of the virus to the host cell receptor Signup and view all the answers

What is a mechanism shared between nucleoside reverse transcriptase inhibitors and ribavirin in targeting viral replication?

Preventing access to virus nucleic acid for replication Signup and view all the answers