6 – Virus Intro

1. Viruses have all the following except
A. definite shape.
B. metabolism.
C. genes.
D. ability to infect host cells.
E. ultramicroscopic size.

B. metabolism.

2. Host cells of viruses include
A. human and other animals.
B. plants and fungi.
C. bacteria.
D. protozoa and algae.
E. All of the choices are correct.

E. All of the choices are correct.

3. The core of every virus particle always contains

E. either DNA or RNA.

4. Classification of viruses into families involves determining all the following characteristics except
A. type of nucleic acid.
B. type of capsid.
C. presence of an envelope.
D. biochemical reactions.
E. nucleic acid strand number.

…E. nucleic acid strand number.

5. Which of the following represents a virus family name?

B. Herpesviridae

6. Virus capsids are made from subunits called

C. capsomeres.

7. Helical and icosahedral are terms used to describe the shapes of a virus

D. capsid.

8. Which of the following is correct about viruses?

A. cannot be seen with a light microscope

9. All of the following pertain to virus envelopes except they

E. are located between the capsid and nucleic acid.

10. Which of the following is not associated with every virus?

A. envelope

11. These structures are used by bacteriophages to attach to host cell receptors.

B. tail fibers

12. Which is incorrect about prophages?

E. occur when temperate phages enter host cells

13. T-even phages

B. infect Escherichia coli cells.

14. The correct sequence of events in viral multiplication is

C. adsorption, penetration, replication, maturation, assembly, release.

15. The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is

B. injection of the viral nucleic acid into the host cell.

16. Viruses acquire envelopes around their nucleocapsids during

D. release.

17. Which of the following will not support viral cultivation?

E. blood agar

18. In general, most DNA viruses multiply in the host cell’s _____, while most RNA viruses multiply in the host cell’s _____.

A. nucleus, cytoplasm

19. Host range is limited by

C. type of host cell receptors on cell membrane.

20. The virus-induced, specific damage to the host cell that can be seen in a light microscope is called

D. cytopathic effects.

21. Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called

C. plaques.

22. Viral growth in bird embryos can cause discrete, opaque spots in the embryonic membranes called

E. pocks.

23. Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called

C. prions.

24. Oncogenic viruses include all the following except

B. measles virus.

25. Which of the following is a type of cytopathic effect?
A. inclusions in the nucleus
B. multinucleated giant cells
C. inclusions in the cytoplasm
D. cells round up
E. All of the choices are correct.

E. All of the choices are correct.

26. Uncoating of viral nucleic acid

B. involves enzymatic destruction of the capsid.

27. Infectious protein particles are called

C. prions.

28. Infectious naked strands of RNA are called

A. viroids.

29. Creutzfeld-Jacob disease is

D. a spongiform encephalopathy of humans.

30. Satellite viruses are

B. dependent on other viruses for replication.

31. All of the following is correct about treating viral diseases except

A. viruses are killed by the same antibiotics that kill bacteria

32. The capsomers are made of

D. protein.

33. Viruses that consist of only a nucleocapsid are considered

C. naked viruses.

34. The nucleocapsid consists of

C. the nucleic acid along with the capsid.

35. Which of the following parts of a virus is not always present?

A. envelope

36. Which of the following viruses did D. Ivanovski and M. Beijerinck work with?

C. tobacco mosaic virus

37. Viruses belong to which of the following Kingdoms?
A. Protists
B. Fungi
C. Archaea
D. Bacteria
E. None of the choices are correct.

E. None of the choices are correct.

38. Which body system is mainly affected by Creutzfeldt-Jakob disease?

C. nervous

39. When a virus enters a lysogenic phase, it means

A. the virus is integrated into the DNA of the host cell and is latent.

40. All of the following are characteristics of viruses except
A. they can be crystallized.
B. they often have a geometric capsid.
C. they have a viscous fluid inside their capsids.
D. they can cause fatal diseases.
E. they can cause mild diseases.

C. they have a viscous fluid inside their capsids.

41. How do enveloped animal viruses exit their host?

A. Budding or exocytosis

42. Clostridium botulinum is made virulent by incorporated prophage genes encoding for the botulinum toxin. What term describes this process?

D. Lysogenic conversion

43. Viruses are ultramicroscopic because they range in size from 2 mm to 450 mm.
True False

False

44. Spikes are glycoproteins of the virus capsid.
True False

True

45. Prophages can be activated into viral replication and enter the lytic cycle. True False

false

46. Viral infections are easier to treat with drugs than bacterial infections. True False

False

47. The International Committee on Taxonomy of Viruses has determined that there are only three orders of viruses. True False

True

48. Bacteriophages do not undergo adsorption to specific host cell receptors prior to penetration.
True False

true

49. When a virus enters a host cell, the viral genes redirect the genetic and metabolic activities of the host cell. True False

True

50. Viral spikes are inserted into the host cell membrane before budding or exocytosis occurs.
True False

True

51. No cases of variant Creutzfeldt-Jakob syndrome linked to eating infected cows have occurred in the United States. True False

True

52. The adeno-associated virus (AAV) and the delta agent are prions. True False

False

53. A _____ is the protein shell around the nucleic acid core of a virus.

capsid

54. Viruses that infect bacteria are specifically called _____.

…Bacteriophages

55. Diagnosis of viral infections sometimes involves analyzing the patient’s blood for specific _____ that the immune system produced against the virus.

…antibodies

56. Two noncellular agents, smaller than viruses, are the infectious proteins called _____, and the infectious RNA strands called _____.

…Prions, Virions

57. Viruses with _____ sense RNA contain the correct message for translation, while viruses with _____ sense RNA must first be converted into a correct message.

positive; negative

58. Freshly isolated animal tissue that is placed in a growth medium and allowed to produce a cell monolayer is referred to as a _____ cell culture.

primary

59. One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as an _____ capsid.

Icosahedral

60. A naked virus does not have an _____.

envelope

61. During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the _____ _____.

bacterial chromosome

62. A common method for cultivating viruses in the lab is to use in vitro systems called _____ cultures.

cell