Virus Quiz : Test your knowledge

1. In host–virus interaction, the term “tropism” refers to:

1. The ability of a virus to cause cancer.
2. The preference of a virus for particular host species or cell types.
3. The capacity of a virus to mutate under environmental stress.
4. The rate at which a virus is cleared from the bloodstream.

2. Which one of the following is most likely to reduce the effectiveness of a pre-existing viral vaccine in a population?

1. Antibiotic resistance in co-infecting bacteria.
2. Antigenic drift in the viral surface proteins.
3. Improved nutrition among the vaccinated population.
4. Increase in the average age at vaccination.

3. The incubation period of a viral disease is influenced by all of the following, EXCEPT:

1. Site of viral entry and replication.
2. Virus replication rate and tissue tropism.
3. Host immune status and response.
4. Colour of the virus when seen under electron microscope.

4. Consider the following statements about enveloped viruses:

1. They generally acquire their envelope from host cell membranes.
2. They are usually more sensitive to heat, detergents and desiccation than non-enveloped viruses.
3. They can never be transmitted via blood.

Which of the statements given above is/are correct?

1. 1 only
2. 1 and 2 only
3. 2 and 3 only
4. 1, 2 and 3

5. With reference to zoonotic viral diseases, which of the following is/are correct?

1. They always require an arthropod vector.
2. They may originate in animals and later adapt to efficient human-to-human transmission.
3. Reservoir hosts often show minimal disease despite harbouring the virus.

Select the correct answer using the code below:

1. 1 and 2 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

6. Which of the following best describes “viral reassortment”?

1. Point mutations occurring in viral RNA over time.
2. Exchange of gene segments between related viruses co-infecting the same cell.
3. Loss of viral envelope during infection.
4. Degradation of viral proteins by host enzymes.

7. In the context of viral pathogenesis, a “carrier state” in humans refers to:

1. Presence of virus in the host with no shedding and no transmission.
2. Presence of virus in the host with or without symptoms but with potential to transmit infection.
3. Infection confined strictly to laboratory personnel.
4. Presence of only viral antibodies but no virus.

8. Which of the following pairs is correctly matched?

Viral term – Description

1. Oncogenic virus – Virus capable of contributing to tumour formation.
2. Lytic infection – Viral infection in which the viral genome always integrates into the host DNA.
3. Persistent infection – Viral infection that is always asymptomatic and of short duration.
4. Abortive infection – Infection where virus multiplies to very high titres and kills the host rapidly.

9. Consider the following statements about interferons in viral infections:

1. They are host-derived proteins with antiviral activity.
2. They act by directly destroying viral particles like antibiotics do bacteria.
3. They can induce the expression of antiviral proteins in neighbouring cells.

Which of the statements given above is/are correct?

1. 1 only
2. 1 and 3 only
3. 2 and 3 only
4. 1, 2 and 3

10. A virus that persists in a host for years with intermittent episodes of disease separated by periods of apparent recovery is best described as causing:

1. Acute self-limited infection
2. Latent infection
3. Strictly localized infection
4. Abortive infection