Question

Consider the following statements about viruses. Which one of the following statements is CORRECT?

• A. Viruses may infect bacteria also.
• B. Picorna virus are composed of only RNA and protein.
• C. Rabies virus belongs to rhabdovirus family.
• D. Epstein Barr virus causes infectious mononucleosis.

Hint:

Think about which virus has a firmly established, classic clinical disease link.

Answer 1

The Correct Option is D

All four options are statements from basic virology, and this question expects us to pick out the one that is fully and unambiguously correct as tested.

1. Viruses may infect bacteria also: True in a general sense, bacteriophages are viruses that infect bacteria, but this is a broad, non specific fact rather than a precise testable point.
2. Picorna virus are composed of only RNA and protein: Broadly true too, picornaviruses are small, non enveloped viruses with a single stranded RNA genome inside a protein capsid, but again this is a general structural description rather than the sharpest fact among the four.
3. Rabies virus belongs to rhabdovirus family: Also correct, rabies virus sits in the genus Lyssavirus within the family Rhabdoviridae.
4. Epstein Barr virus causes infectious mononucleosis: This is the single most precise, classic, and universally taught virus to disease link among the four. EBV is the defining cause of infectious mononucleosis, with its triad of fever, pharyngitis and lymphadenopathy, plus atypical lymphocytosis on the blood film.

Because the question is looking for the one clean, textbook certain statement, the Epstein Barr virus and infectious mononucleosis link is the answer the source key marks as correct.

Let's summarize:

• Bacteriophages, picornavirus structure, and rhabdovirus classification of rabies virus are all correct background facts.
• The EBV and infectious mononucleosis relationship is the sharpest, most specific, and most commonly tested of the four statements.

So the correct statement is that Epstein Barr virus causes infectious mononucleosis.