- 1. Virology is the branch of science that focuses on the study of viruses and viral diseases. Viruses are small infectious agents that can only replicate inside living cells of other organisms. Virologists investigate the structure, classification, evolution, and interactions of viruses, as well as the mechanisms by which viruses cause disease in their hosts. Understanding virology is crucial in the development of treatments and vaccines for viral infections, and in preventing the spread of viral diseases. The field of virology is constantly evolving as new viruses emerge and existing viruses mutate, posing ongoing challenges to public health and medicine.
What is a virus?
A) A plant cell
B) A single-celled organism
C) A small infectious agent that replicates only inside the living cells of other organisms.
D) A type of bacteria
- 2. What is the protein coat surrounding the genetic material of a virus called?
A) Capsid
B) Glycoprotein
C) Envelope
D) Nucleocapsid
- 3. Which of the following is a method of viral entry into a host cell?
A) Photosynthesis
B) Aerobic respiration
C) Endocytosis
D) Mitosis
- 4. What is the outermost layer of some viruses that is composed of lipids and proteins?
A) Envelope
B) Capsid
C) Nucleocapsid
D) Spike protein
- 5. What is the name of the enzyme that retroviruses use to convert RNA into DNA?
A) Ligase
B) RNA polymerase
C) DNA polymerase
D) Reverse transcriptase
- 6. What is antigenic drift in viruses?
A) Sudden change in host specificity
B) Gradual accumulation of mutations in viral genes over time
C) Antibody production against viral proteins
D) Rapid mutation leading to new strains
- 7. Which type of genetic material is found in retroviruses?
A) DNA
B) RNA
C) Protein
D) Lipid
- 8. Which viral disease has been completely eradicated through vaccination?
A) HIV/AIDS
B) Smallpox
C) Zika virus
D) Ebola virus
- 9. Which of the following is a common symptom of viral infections?
A) Yellowish skin
B) Broken bones
C) High blood pressure
D) Fever
- 10. Who is acknowledged for officially beginning the field of virology as a distinct discipline?
A) Ernest William Goodpasture
B) Martinus Beijerinck
C) Rosalind Franklin
D) Frederick Twort
- 11. What term did Martinus Beijerinck use to describe the novel pathogen causing tobacco mosaic disease?
A) Contagium vivum fluidum
B) Bacteriophage
C) Poliovirus
D) Vaccinia virus
- 12. Who first discovered the full structure of the tobacco mosaic virus?
A) Ernst Ruska
B) Wendell Meredith Stanley
C) Rosalind Franklin
D) Heinz Fraenkel-Conrat
- 13. In what year did Dmitri Ivanovsky use the Chamberland filter to study tobacco mosaic virus?
A) 1892
B) 1913
C) 1906
D) 1884
- 14. Who independently discovered bacteriophages in 1917?
A) Félix d'Herelle
B) Paul Frosch
C) Frederick Twort
D) Dmitri Ivanovsky
- 15. Which virus was the first to be crystallized, allowing its structure to be elucidated in detail?
A) Hepatitis B virus
B) Influenza virus
C) Poliovirus
D) Tobacco mosaic virus
- 16. Who were the first to grow poliovirus in cultured cells from aborted human embryonic tissue?
A) H. B. Maitland and M. C. Maitland
B) Ross Granville Harrison, E. Steinhardt, C. Israeli
C) Ernest William Goodpasture and Alice Miles Woodruff
D) John Franklin Enders, Thomas Weller, and Frederick Robbins
- 17. Who invented the electron microscope in 1931?
A) Frederick Twort and Félix d'Herelle
B) John Franklin Enders and Thomas Weller
C) Ernst Ruska and Max Knoll
D) Wendell Meredith Stanley and Rosalind Franklin
- 18. In which year did Wendell Meredith Stanley find that the tobacco mosaic virus was mostly made of protein?
A) 1957
B) 1941
C) 1935
D) 1963
- 19. Who first isolated HIV, a retrovirus, in 1983?
A) Michael Houghton's team at Chiron Corporation
B) Luc Montagnier's team at the Pasteur Institute
C) Howard Temin
D) Baruch Blumberg
- 20. Which virus was discovered by Baruch Blumberg in 1963?
A) Equine arterivirus
B) Human immunodeficiency virus (HIV)
C) Hepatitis B virus
D) Bovine viral diarrhoea
- 21. Who described the first retrovirus in 1965?
A) Michael Houghton
B) Howard Temin
C) Baruch Blumberg
D) Luc Montagnier
- 22. Which scientist's work enabled the production of an effective polio vaccine?
A) John Franklin Enders
B) Frederick Robbins
C) Hilary Koprowski
D) Jonas Salk
- 23. Who demonstrated that purified tobacco mosaic virus RNA and protein coat can assemble to form functional viruses?
A) Heinz Fraenkel-Conrat and Robley Williams
B) Wendell Meredith Stanley
C) Bernal and Fankuchen
D) Ernst Ruska and Max Knoll
- 24. In what year was the bacteriophage first discovered by Frederick Twort?
A) 1957
B) 1915
C) 1898
D) 1946
- 25. Who grew influenza and several other viruses in fertilized chicken eggs in 1931?
A) E. Steinhardt, C. Israeli, and R.A. Lambert
B) Ernest William Goodpasture and Alice Miles Woodruff
C) Ross Granville Harrison
D) H. B. Maitland and M. C. Maitland
- 26. Which virus was first grown on a large scale for vaccine production in the 1950s?
A) Hepatitis B virus
B) Influenza virus
C) Poliovirus
D) Tobacco mosaic virus
- 27. What was commonly used before PCR to confirm viral infections?
A) Immunofluorescence.
B) Microfluidic tests.
C) Complement fixation tests.
D) Lateral flow tests.
- 28. How are results of the FFA expressed?
A) As infectious dose 50%.
B) As focus forming units per milliliter (FFU/mL).
C) As plaque forming units per milliliter.
D) As viral load in copies per milliliter.
- 29. What type of centrifuge is typically used to concentrate viruses?
A) Ordinary laboratory microcentrifuges
B) Ultracentrifuges with a top speed around 100,000 rpm
C) Centrifuges used for blood separation
D) Low speed centrifuges with a top speed of 10,000 rpm
- 30. Which method is used when virus suspensions remain contaminated after differential centrifugation?
A) Sanger sequencing
B) Low speed centrifugation
C) Electrophoresis
D) Buoyant density centrifugation
- 31. What solution is commonly used in buoyant density centrifugation to form a gradient?
A) Polyacrylamide gel
B) Ethidium bromide
C) Caesium chloride
D) Coomasie blue
- 32. Which staining method is used for visualizing nucleic acids in electrophoresis?
A) Radioactive labeling
B) Coomasie blue
C) Ethidium bromide
D) PHYLIP software
- 33. Which software is commonly used to draw phylogenetic trees?
A) Next-generation sequencing (NGS)
B) Coomasie blue
C) PHYLIP
D) Ethidium bromide
- 34. What technique was used to quickly manufacture tests at the start of the COVID-19 pandemic?
A) Phage display techniques
B) Recombination
C) RNA silencing
D) Cloning
- 35. What is a common type of cloning vector used in virology?
A) Recombinant DNA
B) RNA molecules
C) Bacteriophages
D) Laboratory modified plasmids
- 36. What are bacteriophages informally called when they reproduce in bacteria?
A) Viruses
B) Phages
C) Plasmids
D) Recombinants
- 37. Which viruses were among the first to be discovered and are useful for studying virus biology?
A) Coronaviruses
B) Influenza viruses
C) Bacteriophages
D) Rotaviruses
- 38. What technique uses bacteriophages for screening protein DNA sequences?
A) RNA silencing
B) Cloning
C) Phage display techniques
D) Recombination
- 39. What is the process called when genes from different parents are switched in viruses with segmented genomes?
A) Reassortment
B) Recombination
C) RNA silencing
D) Cloning
- 40. Which technique is not as common in nature but is useful in laboratories to study viral genes?
A) Phage display techniques
B) Cloning
C) RNA silencing
D) Recombination
- 41. In what year was the International Committee on Taxonomy of Viruses (ICTV) formed?
A) 1966.
B) 1980.
C) 1999.
D) 1975.
- 42. What classification system is used to supplement the traditional hierarchy for viruses?
A) The Baltimore classification system.
B) The Lwoff-Horne-Tournier system.
C) The ICTV 15-rank classification system.
D) The Linnaean hierarchical system.
- 43. How many realms of viruses have been defined by the ICTV as of 2021?
A) 17
B) 39
C) 6
D) 10
- 44. Which suffix is used for virus families in the ICTV classification system?
A) -viridae
B) -virales
C) -virus
D) -viricetes
- 45. In the Baltimore classification, which group includes viruses with double-stranded DNA genomes?
A) Group III
B) Group IV
C) Group I
D) Group II
- 46. Which type of virus genome is associated with Group VI in the Baltimore classification?
A) ssRNA-RT viruses
B) (−)ssRNA viruses
C) dsRNA viruses
D) dsDNA viruses
- 47. Which suffix is used for suborders in the ICTV classification system?
A) -viricetes
B) -virineae
C) -virales
D) -virus
- 48. How many orders of viruses have been defined by the ICTV as of 2021?
A) 39
B) 65
C) 168
D) 233
- 49. Which group in the Baltimore classification includes viruses with single-stranded RNA that is positive-sense?
A) Group VI
B) Group V
C) Group VII
D) Group IV
- 50. What suffix is used for genera in the ICTV classification system?
A) -virales
B) -virus
C) -viridae
D) -viricetes
- 51. Which group in the Baltimore classification includes viruses with double-stranded DNA that use reverse transcriptase?
A) Group III
B) Group II
C) Group I
D) Group VII
- 52. As of 2021, how many species of viruses have been defined by the ICTV?
A) 39
B) 10,434
C) 233
D) 65
- 53. Which suffix is used for classes in the ICTV classification system?
A) -virus
B) -viridae
C) -viricetes
D) -virales
- 54. What type of genome do Group III viruses have in the Baltimore classification?
A) ssDNA
B) dsRNA
C) dsDNA-RT
D) (+)ssRNA
- 55. In the Baltimore classification, which group includes viruses with single-stranded RNA that is negative-sense?
A) Group VII
B) Group IV
C) Group VI
D) Group V
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