Virology: Virus Classification and Replication

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Questions and Answers

What is the taxonomic rank of 'rotavirus'?

Species name (correct)

Family name

Sub-family name

Genus name

What is the correct sequence of events in the viral cycle?

Uncoating; Attachment and penetration; Synthesis of nucleic acid and proteins; Assembly; Release

Synthesis of nucleic acid and proteins; Uncoating; Attachment and penetration; Release; Assembly

Attachment and penetration; Uncoating; Synthesis of nucleic acid and proteins; Assembly; Release

Attachment and penetration; Synthesis of nucleic acid and proteins; Uncoating; Release; Assembly (correct)

Why is mRNA placed at the center of the Baltimore scheme?

It is convenient due to language conventions among scientists

All viruses must manufacture mRNA to replicate (correct)

mRNA is the genetic material of all viruses

All virus particles contain mRNA

What is true about cellular receptors for viruses?

Successful infection of a cell by a virus may involve interaction with more than one type of receptor Signup and view all the answers

What is the main transmission route of SARS-CoV-2 in humans?

Respiratory transmission Signup and view all the answers

What is the family name of the virus that contains rotavirus?

Reoviridae Signup and view all the answers

What is the purpose of the Baltimore scheme?

To classify viruses based on their genetic material Signup and view all the answers

What is the first step in the viral cycle?

Attachment Signup and view all the answers

Which of the following statements is true about latent virus during pregnancy?

It poses no threat to the newborn Signup and view all the answers

Which test would be most appropriate to confirm a diagnosis of herpes simplex encephalitis?

Polymerase chain reaction (PCR) for viral DNA in cerebrospinal fluid Signup and view all the answers

Which of the following is a recommended therapy for herpes simplex virus genital infection?

Acyclovir Signup and view all the answers

Which of the following viruses causes 'mat herpes'?

Herpes simplex virus type 1 Signup and view all the answers

Which of the following hepatitis viruses could be transmitted as a result of needle stick injury?

Hepatitis B and Hepatitis C Signup and view all the answers

What is the genome of viruses responsible for hepatitis B best described as?

Linear, partially double-stranded DNA Signup and view all the answers

What is the primary concern for health-care workers regarding hepatitis?

Acquiring hepatitis through needle stick injury Signup and view all the answers

Which of the following is NOT a characteristic of herpes simplex virus?

It can be treated with attenuated live virus vaccine Signup and view all the answers

What is the term for the process by which one influenza subtype is replaced by another?

Antigenic shift Signup and view all the answers

Which of the following is NOT a mechanism of antigenic drift in influenza viruses?

Viral transformation Signup and view all the answers

What is the target of oseltamivir (Tamiflu) in the influenza virus lifecycle?

Viral release from the host cell Signup and view all the answers

Which of the following statements is true about the pathogenesis of influenza?

The virus enters the host in airborne droplets Signup and view all the answers

Which of the following specimens is most suitable for isolating the influenza virus?

Nasopharyngeal swab Signup and view all the answers

Which group of viruses is likely to establish latent infections?

Herpesviruses Signup and view all the answers

What is the mechanism of antigenic shift in influenza viruses?

Reassortment between human and animal or avian reservoirs Signup and view all the answers

What is the term for the process by which the influenza virus changes its antigenic properties over time?

Antigenic drift Signup and view all the answers

Study Notes

Virus Classification

Rotavirus is a species name according to the taxonomy of virus.

Viral Cycle

The correct sequence of the viral cycle is: Attachment and penetration; Uncoating; Synthesis of nucleic acid and proteins; Assembly; Release.

Baltimore Scheme

mRNA is placed at the center of the Baltimore scheme because all viruses must manufacture mRNA to replicate.

Cellular Receptors for Viruses

Viruses usually initiate infection by first interacting with receptors on the surface of cells.
Cellular receptors for viruses have known cellular functions.
Successful infection of a cell by a virus may involve interaction with more than one type of receptor.

SARS-CoV-2 Transmission

The main transmission route of SARS-CoV-2 is respiratory transmission.

Herpes Simplex Virus

Herpes simplex virus can cause encephalitis, which can be diagnosed using PCR for viral DNA in cerebrospinal fluid.
Acyclovir is a recommended therapy for herpes simplex virus genital infection.
Herpes simplex virus can cause a rash called "mat herpes" that is contagious among wrestlers.

Hepatitis

Hepatitis B and Hepatitis C can be transmitted through needle stick injury.
The genome of viruses responsible for hepatitis B is partially double-stranded DNA.

Influenza Virus

Influenza virus genome is subject to antigenic drift, which involves mutations caused by viral RNA polymerase.
Antigenic drift can predominate under selective host population immune pressures.
Oseltamivir (Tamiflu) works by preventing the release of mature virions from the host cell.
The pathogenesis of influenza involves the virus entering the host in airborne droplets, but viremia is not common.
Nasopharyngeal swab is the best specimen for isolating the influenza virus.
Herpesviruses are likely to establish latent infections.

Viral Infections

Genital herpes infections can be recurrent, and lesions typically last less than 1 month.

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Description

Test your knowledge of virus classification, viral cycle, Baltimore scheme, and cellular receptors for viruses. Understand the taxonomy of viruses, stages of viral replication, and how viruses interact with host cells.