Asked in PMC Practice Test 27 (2021) 2021Moderate

_ are amongst smallest known virus.

Correct answer: B. Parvoviruses

  • A. Picornavirus
  • B. Parvoviruses
  • C. Herpes virus
  • D. Rotavirus

Explanation

Option B is correct since parvoviruses are the smallest icosahedral particles about 18-26 nm in diameter. Option A is incorrect since picornaviruses are larger than parvoviruses with a diameter of 22-30nm. Option C is incorrect since the herpesviral is a large family of double-stranded and DNA viruses that are larger than both parvoviruses and picornaviruses with a diameter of about 120-260nm. Option D is incorrect since rotaviruses are larger than both parvovirus and picornaviruses with a diameter of about 70 nm when a double-layered capsid is present and 55 nm when this capsid is absent.

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