1. Virology is the study of:
(A) Bacteria
(B) Viruses
(C) Fungi
(D) Algae
2. Viruses are:
(A) Multicellular organisms
(B) Single-celled organisms
(C) Acellular infectious agents
(D) Bacteria
3. The genetic material of a virus can be:
(A) Only DNA
(B) DNA or RNA
(C) Only RNA
(D) Protein only
4. Viruses lack:
(A) Protein coat
(B) Genetic material
(C) Cellular structure and metabolism
(D) Ability to infect
5. The protein coat of a virus is called:
(A) Capsule
(B) Cell wall
(C) Membrane
(D) Capsid
6. Some viruses have an outer lipid layer called:
(A) Cell wall
(B) Envelope
(C) Capsule
(D) Cytoplasm
7. Viruses reproduce by:
(A) Budding independently
(B) Binary fission
(C) Replication inside host cells
(D) Spore formation
8. Viruses that infect bacteria are called:
(A) Retroviruses
(B) Bacteriophages
(C) Oncogenic viruses
(D) Mycoviruses
9. Lytic bacteriophages:
(A) Only infect humans
(B) Integrate into host genome
(C) Do not replicate
(D) Destroy the host cell after replication
10. Lysogenic bacteriophages:
(A) Are only RNA viruses
(B) Immediately lyse host cells
(C) Integrate their DNA into host genome
(D) Do not infect bacteria
11. Retroviruses have:
(A) Only proteins
(B) DNA genome only
(C) RNA genome and reverse transcriptase
(D) Double-stranded DNA only
12. HIV is a:
(A) Plant virus
(B) DNA virus
(C) Bacteriophage
(D) Retrovirus
13. Influenza virus is a:
(A) RNA virus
(B) DNA virus
(C) Retrovirus
(D) Bacteriophage
14. Smallpox virus is a:
(A) RNA virus
(B) DNA virus
(C) Retrovirus
(D) Bacteriophage
15. Vaccines help prevent viral infections by:
(A) Stimulating immunity
(B) Killing viruses directly
(C) Blocking oxygen supply
(D) Only reducing symptoms
16. Edward Jenner developed a vaccine against:
(A) Smallpox
(B) Polio
(C) Rabies
(D) Influenza
17. Rabies virus is transmitted by:
(A) Food only
(B) Airborne droplets only
(C) Water only
(D) Animal bites
18. Poliovirus affects:
(A) Nervous system
(B) Digestive system only
(C) Skin only
(D) Muscles only
19. Measles virus belongs to:
(A) Retroviruses
(B) DNA viruses
(C) RNA viruses
(D) Bacteriophages
20. Viral genome can be:
(A) Only double-stranded RNA
(B) Only single-stranded DNA
(C) Single-stranded or double-stranded, DNA or RNA
(D) Only protein
21. Virus size is usually in the range of:
(A) 1–5 cm
(B) 1–10 mm
(C) 1–10 μm
(D) 20–300 nm
22. Viral replication follows:
(A) Attachment, entry, replication, assembly, release
(B) Binary fission only
(C) Budding only
(D) Spore formation only
23. Viral diseases in plants include:
(A) Smallpox
(B) Influenza
(C) Rabies
(D) Mosaic disease
24. Viral diseases in animals include:
(A) Salmonellosis
(B) Tuberculosis
(C) Anthrax
(D) Foot-and-mouth disease
25. Viral diseases in humans include:
(A) Typhoid
(B) Tuberculosis
(C) Malaria
(D) Influenza, HIV, COVID-19
26. DNA viruses replicate in:
(A) Outside host
(B) Cytoplasm only
(C) Host cell nucleus
(D) Mitochondria only
27. RNA viruses replicate in:
(A) Outside host
(B) Nucleus only
(C) Host cell cytoplasm
(D) Lysosomes only
28. Enveloped viruses acquire their envelope from:
(A) DNA only
(B) Viral capsid
(C) Host cell membrane
(D) Bacterial cell wall
29. Non-enveloped viruses are also called:
(A) Retroviruses
(B) Naked viruses
(C) Bacteriophages
(D) Mycoviruses
30. Viruses are obligate parasites because:
(A) They require host machinery for replication
(B) They produce their own energy
(C) They can survive independently
(D) They perform photosynthesis
31. Bacteriophages were first discovered by:
(A) Frederick Twort
(B) Louis Pasteur
(C) Robert Koch
(D) Antonie van Leeuwenhoek
32. Lytic cycle results in:
(A) No replication
(B) Integration into host genome
(C) Dormancy only
(D) Immediate lysis of host cell
33. Lysogenic cycle results in:
(A) Virus cannot replicate
(B) Immediate host lysis
(C) Viral genome integrates into host DNA
(D) Only RNA viruses
34. Reverse transcriptase enzyme is found in:
(A) DNA viruses only
(B) Retroviruses
(C) Bacteriophages only
(D) All viruses
35. Oncogenic viruses can cause:
(A) Cancer
(B) Fever only
(C) Cough only
(D) Skin rashes only
36. Hepatitis B virus is a:
(A) DNA virus
(B) RNA virus
(C) Retrovirus
(D) Bacteriophage
37. Hepatitis C virus is a:
(A) Retrovirus
(B) DNA virus
(C) RNA virus
(D) Bacteriophage
38. Ebola virus belongs to:
(A) RNA viruses
(B) DNA viruses
(C) Retroviruses
(D) Bacteriophages
39. Viral capsid is made up of:
(A) RNA only
(B) Lipids
(C) DNA only
(D) Protein subunits called capsomeres
40. Virus taxonomy includes:
(A) Order, family, genus, species
(B) Kingdom, phylum, class
(C) Family, genus only
(D) Only species
41. Viral envelope contains:
(A) Only lipids
(B) Only DNA
(C) Only RNA
(D) Glycoproteins for host recognition
42. Virus-host specificity is determined by:
(A) Environmental factors only
(B) Host DNA only
(C) Viral RNA only
(D) Surface receptors and viral attachment proteins
43. Plant viruses are usually transmitted by:
(A) Water only
(B) Insects like aphids
(C) Air only
(D) Soil only
44. Influenza virus undergoes:
(A) Antigenic shift and drift
(B) Binary fission
(C) Conjugation
(D) Budding only
45. Viral capsid shapes include:
(A) Square only
(B) Rod-shaped only
(C) Spherical only
(D) Helical, icosahedral, complex
46. Viral culture can be done in:
(A) Only broth media
(B) Only soil
(C) Only water
(D) Living cells, embryonated eggs, or cell lines
47. Bacteriophage therapy is used to:
(A) Treat bacterial infections
(B) Kill viruses
(C) Treat fungal infections
(D) Promote plant growth
48. Viral pathogenicity depends on:
(A) Virulence factors and host immunity
(B) Temperature only
(C) pH only
(D) Oxygen only
49. Antiviral drugs work by:
(A) Enhancing viral entry
(B) Killing host cells
(C) Inhibiting viral replication
(D) Increasing virulence
50. Virology is important for:
(A) Only plant growth
(B) Medicine, agriculture, and biotechnology
(C) Only soil health
(D) Only industry