Micro - Ch 6

11. Viral spikes A. are always present on enveloped viruses. B. attach the viral capsid and envelope. C. allow bacteria to evade host defenses. D. are derived from host proteins. E. are for recognition among the various types of viruses.

A

13. Which of the following is not associated with every virus? A. Envelope B. Capsomeres C. Capsid D. Nucleic acid E. Genome

A

17. Viruses with _____-sense RNA contain the correct message for translation, while viruses with _____-sense RNA must first be converted into a correct message. A. positive; negative B. negative; positive C. primary; secondary D. secondary; primary E. intermediate; primary

A

28. Viruses attach to their hosts via ______. A. host glycoproteins B. host phospholipids C. viral phospholipids D. viral flagella E. carbohydrate attachments of the viral capsid

A

3. Viruses ______. A. cannot be seen in a light microscope B. are prokaryotic C. contain 70S ribosomes D. undergo binary fission

A

40. Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called ______. A. latent B. oncogenic C. prions D. viroids E. delta agents

A

48. When a bacterium acquires a trait from its temperate phage, it is called ______. A. transformation B. lysogenic conversion C. viral persistence D. transcription E. translation

B

15. Reverse transcriptase synthesizes A. a positive RNA strand from a negative RNA strand. B. a negative RNA strand from a positive RNA strand. C. viral RNA from DNA. D. viral DNA from RNA.

D

30. The process of dissolving the envelope and capsid to release the viral nucleic acid is ______. A. adsorption B. penetration C. uncoating D. synthesis E. assembly

C

49. Which of the following will not support viral cultivation? A. Live lab animals B. Embryonated bird eggs C. Primary cell cultures D. Continuous cell cultures E. All of the choices will support viral cultivation.

E

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

FALSE

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

TRUE

6. A/an _____ is the protein shell around the nucleic acid core of a virus. A. capsomere B. capsid C. spike D. envelope E. monolayer

B

8. A naked virus only has a/an ______. A. capsomere B. nucleocapsid C. envelope D. antigenic surface

B

46. What type of phage enters an inactive prophage stage? A. Primary B. Secondary C. Temperate D. Temporary E. Transformed

C

50. Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called ______. A. patches B. buds C. plaques D. cytopathic effects E. pocks

C

22. Viruses acquire envelopes around their nucleocapsids during ______. A. replication B. assembly C. adsorption D. release E. penetration

D

31. Which of the following occurs during assembly? A. The nucleocapsid is formed. B. New viral nucleic acid is formed. C. Viral spikes insert in host cell membrane. D. The nucleocapsid is formed and viral spikes insert in host cell membrane. E. The viral envelope and the host cell membrane fuse.

D

37. Which of the following is incorrect about prophages? A. Present when the virus is in lysogeny B. Formed when viral DNA enters the bacterial chromosome C. Replicated with host DNA and passed on to progeny D. Cause lysis of host cells E. Occur when temperate phages enter host cells

D

45. During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the host ______. A. cytoplasm B. nucleus C. nucleolus D. DNA E. cell membrane

D

10. All of the following pertain to virus envelopes except A. gained as a virus leaves the host cell membrane. B. gained as a virus leaves the nuclear membrane. C. contain special virus proteins. D. help the virus particle attach to host cells. E. located between the capsid and nucleic acid.

E

12. The core of every virus particle always contains ______. A. DNA B. capsomeres C. enzymes D. DNA and RNA E. either DNA or RNA

E

39. The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is A. adsorption to the host cells. B. injection of only the viral nucleic acid into the host cell. C. host cell synthesis of viral enzymes and capsid proteins. D. assembly of nucleocapsids. E. replication of viral nucleic acid.

B

16. A negative RNA virus must first A. synthesize a DNA copy of its genome. B. synthesize a negative RNA copy of its genome. C. synthesize a positive RNA copy of its genome. D. transcribe reverse transcriptase. E. transcribe RNA polymerase.

C

7. One of the principal viral capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a/an _____ capsid. A. spiked B. complex C. icosahedral D. helical E. buckeyball

C

14. Viral nucleic acid types include which of the following? A. Double-stranded DNA B. Single-stranded DNA C. Double-stranded RNA D. Single-stranded RNA E. All of the choices are correct.

E

42. In transduction, the viral genome A. initiates lysis of the host. B. includes DNA from the previous host. C. is replicated in the cytoplasm. D. is replicated in the nucleus.

B

21. The correct sequence of events in viral multiplication is A. penetration, uncoating, synthesis, adsorption, assembly, and release. B. uncoating, penetration, synthesis, assembly, absorption, and release. C. adsorption, penetration, uncoating, synthesis, assembly, and release. D. assembly, synthesis, uncoating, release, penetration, and adsorption. adsorption, release, synthesis, uncoating, assembly, and penetration.

C

24. Host range is limited by the A. type of nucleic acid in the virus. B. age of the host cell. C. type of host cell receptors on cell membrane. D. size of the host cell.

C

4. Viral capsids are made from subunits called ______. A. envelopes B. spikes C. capsomeres D. prophages E. peptones

C

44. Viruses that infect bacteria are specifically called ______. A. viroids B. prions C. bacteriophages D. satellite viruses

C

18. 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. number of strands in the nucleic acid.

D

27. The envelope of enveloped viruses A. is identical to the host plasma membrane. B. is only composed of host endomembrane. C. does not contain spikes. D. is obtained by viral budding or exocytosis. E. makes the virus very susceptible to drug therapy.

D

41. Uncoating of viral nucleic acid A. does not occur in bacteriophage multiplication. B. involves enzymatic destruction of the capsid. C. occurs during penetration in the multiplication cycle. D. occurs before replication. E. All of the choices are correct.

E

43. Lysogeny refers to A. altering the host range of a virus. B. the latent state of herpes infections. C. virions exiting host cell. D. the viral genome inserting into bacterial host chromosome.

D

47. The activation of a prophage is called ______. A. activation B. lysogeny C. transformation D. induction E. adsorption

D

5. Helical and icosahedral are terms used to describe the shape of a viral ______. A. spike B. capsomere C. envelope D. capsid E. core

D

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

E

26. Which of the following is/are type(s) of cytopathic effects? A. Inclusions in the nucleus B. Multinucleated giant cells C. Inclusions in the cytoplasm D. Rounding of cells E. All of the choices are correct.

E

23. In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____. A. nucleus; cytoplasm B. cytoplasm; cell membrane C. cell membrane; cytoplasm D. cytoplasm; nucleus E. nucleus; endoplasmic reticulum

A

33. Persistent viruses that can reactivate periodically are ______. A. chronic latent viruses B. oncoviruses C. syncytia D. inclusion bodies E. cytopathic

A

35. New, nonenveloped virus release occurs by ______. A. lysis B. budding C. exocytosis D. both lysis and budding E. both budding and exocytosis

A

9. Which of the following is not a typical capsid shape? A. Tetrahedral B. Complex C. Helical D. Icosahedron

A

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

B

32. Mammalian viruses capable of starting tumors are ______. A. chronic latent viruses B. oncoviruses C. syncytia D. inclusion bodies

B

38. T-even phages ______. A. include the poxviruses B. infect Escherichia coli cells C. enter host cells by engulfment D. have helical capsids

B

34. Which of the following is not a characteristic of a transformed cell? A. Viral nucleic acid integrated into host DNA B. Decreased growth rate C. Alterations in chromosomes D. Changes in cell surface molecules E. Capacity to divide indefinitely

B

36. What structures are used by bacteriophages to attach to host cell receptors? A. Viral sheaths B. Tail fibers C. Nucleic acids D. Capsid heads

B

19. Which of the following represents a virus family name? A. Herpes simplex virus B. Herpesviridae C. Picornavirus D. Enterovirus E. Hepatitis B virus

B

20. Which of the following is not a viral order in the classification system? A. Caudovirales B. Vaccinia virus C. Nidovirales D. Mononegavirales

B

25. Oncogenic viruses include all the following except ______. A. hepatitis B virus B. measles virus C. Papillomavirus D. HTLV-I and HTLV-II viruses E. Epstein-Barr virus

B

29. Viral tissue specificities are called ______. A. ranges B. virions C. receptacles D. tropisms E. uncoating

D

64. Viruses are used to produce vaccines for prevention of certain viral infections. True False

TRUE