Virology: 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

Sample item

A new influenza A strain with a novel haemagglutinin subtype causes a pandemic. Which process best explains the abrupt appearance of this strain?

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

The answer and the reasoning

A. Antigenic shift by genetic reassortment between human and animal viruses

The influenza A genome has eight segments of negative-sense RNA. Co-infection of one cell with human and animal strains allows reassortment of segments, producing an abrupt major antigenic change (shift) responsible for pandemics, whereas point mutations cause minor drift and seasonal epidemics.

Option by option

  • A. Antigenic shift by genetic reassortment between human and animal viruses (correct)

    Correct. Reassortment of genome segments produces abrupt major changes.

  • B. Lysogenic conversion by a bacteriophage

    Lysogenic conversion occurs in bacteria infected by temperate phages.

  • C. Antigenic drift by point mutations

    Drift is a gradual change by point mutation and causes epidemics, not pandemics.

  • D. Recombination by integration into host DNA

    Influenza is an RNA virus that does not integrate into host DNA.

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 A, Antigenic shift by genetic reassortment between human and animal viruses. The influenza A genome has eight segments of negative-sense RNA.

Why is "Lysogenic conversion by a bacteriophage" not the answer?

Lysogenic conversion occurs in bacteria infected by temperate phages.

Why is "Antigenic drift by point mutations" not the answer?

Drift is a gradual change by point mutation and causes epidemics, not pandemics.

Why is "Recombination by integration into host DNA" not the answer?

Influenza is an RNA virus that does not integrate into host DNA.

What concept does this question test?

It tests Virology in Microbiology. Co-infection of one cell with human and animal strains allows reassortment of segments, producing an abrupt major antigenic change (shift) responsible for pandemics, whereas point mutations cause minor drift and seasonal epidemics.

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?

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.