Virology: viral structure: practice question

A Microbiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Microbiology · Virology: viral structure

Sample item

A laboratory finds that an unidentified virus loses its infectivity after treatment with diethyl ether. Which conclusion is most appropriate?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. The virus has a lipid envelope

Lipid solvents such as ether, chloroform and detergents dissolve the lipid envelope and inactivate enveloped viruses. Naked icosahedral viruses such as enteroviruses and adenoviruses resist ether, bile and acid. Ether sensitivity says nothing about the nature of the genome.

Option by option

  • A. The virus is a prion-like agent

    Prion-like agents are not inactivated by ether in this manner and are not viruses.

  • B. The virus has a lipid envelope (correct)

    Correct. Ether sensitivity indicates the presence of an envelope.

  • C. The virus has a double-stranded DNA genome

    Genome type cannot be deduced from ether sensitivity.

  • D. The virus has a naked capsid and will survive bile and gastric acid

    Naked capsid viruses are ether resistant, so an ether-labile virus does not fit this.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Microbiology questions

Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is B, The virus has a lipid envelope. Lipid solvents such as ether, chloroform and detergents dissolve the lipid envelope and inactivate enveloped viruses.

Why is "The virus is a prion-like agent" not the answer?

Prion-like agents are not inactivated by ether in this manner and are not viruses.

Why is "The virus has a double-stranded DNA genome" not the answer?

Genome type cannot be deduced from ether sensitivity.

Why is "The virus has a naked capsid and will survive bile and gastric acid" not the answer?

Naked capsid viruses are ether resistant, so an ether-labile virus does not fit this.

What concept does this question test?

It tests Virology: viral structure in Microbiology. Naked icosahedral viruses such as enteroviruses and adenoviruses resist ether, bile and acid. Ether sensitivity says nothing about the nature of the genome.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Virology: viral structure?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.