Biology 220: Microbiology
Chapter 6: An Introduction to Viruses
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Part I – Multiple Choice/True & False
1.
A ______ is a non-cellular infectious agent that is not a virus and does not belong in a category all by themselves.
a. virion
b. bacteriophage
c. prion
d. obligate intracellular parasite
2. Which of the following is a naturally occurring product in human cells that is used for treating and preventing viral
infections?
a. interferon
b. virion
c. prion
d. prophage
3. ______ viruses enter the host cells nucleus and are replicated and assembled there, whereas ______ viruses are
replicated and assembled in the cytoplasm.
a. DNA; cDNA
b. DNA; RNA
c. RNA; RNA
d. RNA; DNA
4. A host cell is required for viral replication.
a. true
b. false
5. The sum total of the genetic information carried by an organism is known as its _______.
a. DNA
b. RNA
c. genome
d. genetics
6. Viruses …
a. are not cellular
b. contain DNA and RNA
c. are obligate intracellular parasites
d. not alive
e. a, c, and d
7. Which of the following is not a characteristic of viruses?
a. they range from 20nm to 450nm in diameter
b. their nucleic acid can be double strand DNA, single stranded DNA, double stranded RNA, or single stranded RNA
c. they are facultative intracellular parasites
d. not cellular in nature
8. Viruses invade only animal, plant, and bacterial cells.
a. true
b. false
9. Which of the following does not best describe a virus?
a. genetic parasites that take over the host cell’s metabolism and synthetic machinery
b. obligate intracellular parasites
c. DNA or RNA based organism
d. both a and c
10. Which of the following do viruses not contain?
a. carbohydrates
b. proteins
c. nucleic acids
d. they contain all of the above
11. The __________ are very large DNA viruses that lack a typical capsid and are covered by a dense layer of lipoporteins
and coarse fibrils on their outer surface.
a. poxviruses
b. bacteriophages
c. adenoviruses
d. rhinoviuses
12. ____________ have a polyhedral head as well as a helical tail and fibers for attachment to the host cell.
a. poxviruses
b. bacteriophages
c. rhinoviruses
d. adenoviruses
13. There are more DNA viruses than RNA viruses.
a. true
b. false
14. Which of the following is not a way to classify viruses?
a. animal, plant, bacterial
b. enveloped or naked
c. DNA or RNA
d. helical or icosahedral
e. number of enzymes produced
15. Which of the following is not a function of the capsid or envelope?
a. protects DNA or RNA
b. introduces DNA or RNA into host
c. stimulate immune system
d. produce more proteins
16. Identical protein subunits are known as
a. capsids
b. capsomers
c. bacteriophages
d. amino acids
17. Rod shaped capsomers bonded together to form a series of hollow discs.
a. helical capsid
b. icosahedron capsid
c. bacillus capsid
d. none of the above
18. A three dimensional, 20 sided figure with 12 evenly spaced corners is called a _________.
a. helical capsid
b. icosahedron capsid
c. bacillus capsid
d. none of the above
19. Which of the following is not a phase in the life cycle of animal viruses?
a. penetration
b. uncoating
c. synthesis
d. degredation
e. assembly
20. A fully formed, extracellular virus particle that is virulent is called a prion.
a. true
b. false
21. Mammalian viruses that are capable of initiating tumors are called ________.
a. oncogenes
b. inclusion bodies
c. oncoviruses
d. all of the above
22. A virus is a tiny infectious
a. cell
b. living thing
c. particle
d. nucleic acid
23. Viruses are known to infect
a. plants
b. animals
c. fungi
d. all organisms
24. The nucleic acid of a virus is
a. DNA only
b. RNA only
c. both DNA and RNA
d. either DNA or RNA
e. neither DNA or RNA
25. The general steps in a viral multiplication cycle are
a. adsorption, penetration, synthesis, assembly, and release
b. endocytosis, uncoating, replication, assembly, and budding
c. adsorption, uncoating, duplication, assembly, and lysis
d. endocytosis, penetration, replication, maturation, and exocytosis
Part II – Matching
____26. Capsid
____27. Nucleocapsid
____28. Envelope
____29. Capsomer
____30. Rhabdoviruses
____31. Togavisues
____32. Adenoviruses
____33. Bunyaviruses
____34. Picornaviruses
____35. Reoviruses
____36. Adsorption
____37. Penetration
____38. Replication
____39. Assembly
____40. Maturation
____41. Release
a.respiratory enteric orphan virus
b. cloaklike envelope
c. identical building blocks that make capsid
d. put components into whole
e. small RNA virus
f. capsid and nucleic acid
g. virus enters cell
h. bullet shaped
i. shell
j. originally isolated in Bunyamwera, Africa
k. external to capsid
l. copy of viral genome within cell
m. attachment to cell surface
n. escape from host cell
o. adenoids
p. produce new components and build
Part III – True or False (label each question either true or false based on characteristics of viruses)
____42. Obligate intracellular parasites
____43. Cellular in nature
____44. Nucleic acid can be DNA, RNA, or both
____45. Nucleic acid can be double stranded DNA, double stranded RNA, Single stranded RNA, or single stranded DNA
____46. Basic structure consists of protein surrounding nucleic acid.
____47. Size range is from 50mm to 9000mm.
____48. Lack machinery for synthesizing proteins.
____49. Have enzymes for most metabolic processes.
____50. Do not independently fulfill the characteristics of life