Complete Exam Guide Subject-wise practice platform
0 XP
Virology

Virus Classification Practice Questions

18 free Virus Classification practice questions for the Microbiology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.

Practice in Quiz Mode

Question 1 of 18 Medium

On what basis are viruses primarily classified?

  1. A Color and size
  2. B Type of genetic material
  3. C Host immune response
  4. D Shape and size of host cell

Correct answer: Type of genetic material

Viruses are mainly classified based on their genetic material, whether DNA or RNA. This is a key feature in viral taxonomy.

Question 2 of 18 Medium

Which type of virus contains double-stranded DNA?

  1. A Class I
  2. B Class II
  3. C Class III
  4. D Class V

Correct answer: Class I

Class I viruses in the Baltimore system have double-stranded DNA genomes. They replicate using host or viral DNA polymerases.

Question 3 of 18 Medium

Which virus class contains single-stranded RNA that acts as mRNA?

  1. A Class I
  2. B Class II
  3. C Class IV
  4. D Class VII

Correct answer: Class IV

Class IV viruses have positive-sense single-stranded RNA that can directly function as mRNA. This allows immediate protein synthesis.

Question 4 of 18 Medium

Which virus class requires reverse transcription?

  1. A Class I
  2. B Class III
  3. C Class VI
  4. D Class V

Correct answer: Class VI

Class VI viruses, also known as retroviruses, use reverse transcriptase to convert RNA into DNA. This DNA integrates into the host genome.

Question 5 of 18 Medium

Which type of RNA virus has negative-sense RNA?

  1. A Class IV
  2. B Class I
  3. C Class II
  4. D Class V

Correct answer: Class V

Class V viruses have negative-sense RNA that must be converted into positive-sense RNA before translation. They carry RNA-dependent RNA polymerase.

Question 6 of 18 Medium

Which family does the influenza virus belong to?

  1. A Paramyxoviridae
  2. B Papillomaviridae
  3. C Herpesviridae
  4. D Orthomyxoviridae

Correct answer: Orthomyxoviridae

Influenza viruses belong to the Orthomyxoviridae family. They are segmented RNA viruses.

Question 7 of 18 Medium

Which virus family includes HIV?

  1. A Adenoviridae
  2. B Poxviridae
  3. C Flaviviridae
  4. D Retroviridae

Correct answer: Retroviridae

HIV belongs to the Retroviridae family. It is a retrovirus that uses reverse transcription.

Question 8 of 18 Medium

Which classification considers viral morphology?

  1. A Genetic classification
  2. B Functional classification
  3. C Chemical classification
  4. D Structural classification

Correct answer: Structural classification

Structural classification is based on virus shape, capsid symmetry, and presence of envelope. It helps identify viral types.

Question 9 of 18 Medium

Which virus has a segmented genome?

  1. A Cytomegalovirus
  2. B Herpesvirus
  3. C Poliovirus
  4. D Influenza virus

Correct answer: Influenza virus

Influenza virus has a segmented RNA genome. This allows genetic reassortment and variation.

Question 10 of 18 Medium

Which virus family contains DNA viruses with complex structure?

  1. A Poxviridae
  2. B Reoviridae
  3. C Orthomyxoviridae
  4. D Picornaviridae

Correct answer: Poxviridae

Poxviridae are large DNA viruses with complex structures. They replicate in the cytoplasm.

Question 11 of 18 Medium

Which group includes viruses with single-stranded DNA?

  1. A Class II
  2. B Class III
  3. C Class IV
  4. D Class VI

Correct answer: Class II

Class II viruses contain single-stranded DNA genomes. They must convert to double-stranded DNA before replication.

Question 12 of 18 Medium

Which virus classification is based on replication strategy?

  1. A Morphological classification
  2. B Host classification
  3. C Baltimore classification
  4. D Size classification

Correct answer: Baltimore classification

The Baltimore classification groups viruses based on how they replicate and produce mRNA. It links genome type to replication.

Question 13 of 18 Medium

Which virus is an example of a non-enveloped virus?

  1. A HIV
  2. B Influenza
  3. C Adenovirus
  4. D Herpesvirus

Correct answer: Adenovirus

Adenovirus is a non-enveloped virus with an icosahedral capsid. It is more resistant to environmental conditions.

Question 14 of 18 Medium

Which virus family contains positive-sense RNA viruses?

  1. A Picornaviridae
  2. B Orthomyxoviridae
  3. C Poxviridae
  4. D Adenoviridae

Correct answer: Picornaviridae

Picornaviridae includes positive-sense RNA viruses like poliovirus. Their RNA can directly serve as mRNA.

Question 15 of 18 Medium

Which classification groups viruses by the organisms they infect?

  1. A Host-based classification
  2. B Genetic classification
  3. C Structural classification
  4. D Baltimore classification

Correct answer: Host-based classification

Host-based classification groups viruses according to the organisms they infect, such as animal, plant, or bacterial viruses.

Question 16 of 18 Medium

Which virus family includes Epstein-Barr virus?

  1. A Herpesviridae
  2. B Retroviridae
  3. C Flaviviridae
  4. D Paramyxoviridae

Correct answer: Herpesviridae

Epstein-Barr virus, also known as Human herpesvirus 4, belongs to the Herpesviridae family. These are enveloped DNA viruses.

Question 17 of 18 Medium

Which virus type requires RNA-dependent RNA polymerase?

  1. A DNA viruses
  2. B Negative-sense RNA viruses
  3. C Retroviruses
  4. D Double-stranded DNA viruses

Correct answer: Negative-sense RNA viruses

Negative-sense RNA viruses require RNA-dependent RNA polymerase to synthesize mRNA. This enzyme is carried within the virus.

Question 18 of 18 Medium

T4 and lambda belong to which group of viruses?

  1. A Animal viruses
  2. B Plant viruses
  3. C Bacterial viruses
  4. D Protozoan viruses

Correct answer: Bacterial viruses

T4 and lambda are bacteriophages, which are viruses that infect bacteria. They are classified as bacterial viruses based on their prokaryotic hosts.

0 / 18 answered