Virus Quiz : Test your knowledge

1. With reference to viruses, which of the following statements is/are correct?

1. All viruses are obligate intracellular parasites.
2. All viruses contain both DNA and RNA as genetic material.
3. Some viruses can be crystallized outside the host cell.

Select the correct answer using the code below:

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

2. Consider the following statements regarding RNA viruses:

1. They mutate generally faster than DNA viruses.
2. All RNA viruses necessarily have an envelope.
3. Some RNA viruses can directly serve as mRNA inside host 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

3. Which of the following best describes a retrovirus?

1. A DNA virus that replicates entirely in the cytoplasm.
2. An RNA virus that uses reverse transcriptase to form DNA in the host cell.
3. A virus that infects only bacteria.
4. A virus that lacks a protein coat.

4. With reference to bacteriophages, which of the following statements is/are correct?

1. They infect bacterial cells and may follow either lytic or lysogenic cycles.
2. They are used as tools in molecular biology and genetic engineering.
3. They are incapable of transferring bacterial genes between bacteria.

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

5. Which of the following best explains why antibiotics are generally ineffective against viral infections?

1. Viruses lack the metabolic pathways and cell wall targets that antibiotics act upon.
2. Viruses are too small to be detected by antibiotics.
3. Viruses become immediately dormant in human tissues.
4. Viruses are always resistant to all chemical agents.

6. In the context of public health, “herd immunity” against a viral disease depends primarily on which of the following?

1. Proportion of immune individuals in the population.
2. Basic reproduction number (R₀) of the virus.
3. Ability of the virus to survive outside the host indefinitely.

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

7. Consider the following pairs:

Virus – Primary mode of transmission

1. Hepatitis B virus – Blood and body fluids
2. Rabies virus – Faeco-oral route
3. Influenza virus – Respiratory droplets
4. Human papillomavirus (HPV) – Vector-borne

Which of the pairs given above is/are correctly matched?

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

8. With reference to viral vaccines, which of the following statements is/are correct?

1. Live attenuated vaccines generally induce stronger and longer-lasting immunity than inactivated vaccines.
2. Inactivated vaccines can be safely given to severely immunocompromised individuals in most cases.
3. Both live attenuated and inactivated viral vaccines always provide sterilizing immunity.

Select the correct answer using the code below:

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

9. In the context of viral replication, what does the “latent period” refer to?

1. The time from viral entry into a host organism to the first appearance of clinical symptoms.
2. The time from viral entry into a single host cell until mature virions are first released.
3. The duration for which a virus remains viable on inanimate surfaces.
4. The cumulative time taken for viral genetic material to integrate into the host genome.

10. Which of the following characteristics can help distinguish viruses from prions?

1. Presence of nucleic acid as genetic material.
2. Ability to be inactivated by agents that degrade nucleic acids.
3. Exclusive proteinaceous nature without any nucleic acid.

Select the correct answer using the code below:

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