Micro Chapter 6

Question 1

The genetic material found in a virion is usually 
  A) DNA only 
  B) RNA only 
  C) Either DNA or RNA 
  D) Neither DNA nor RNA

Answer 1

C

Question 2

Viral particles can be composed of 
  A) DNA or RNA 
  B) A coat of protein 
  C) Layers of carbohydrates, lipids, and additional proteins 
  D) All of the above

Answer 2

D

Question 3

The best microscopic method for studying viruses is 
  A) Bright-field microscopy 
  B) Dark-field microscopy 
  C) Electron microscopy 
  D) Atomic force microscopy

Answer 3

C

Question 4

The function of the viral capsid is to 
  A) Protect the viral genome 
  B) Encode viral proteins 
  C) Replicate the viral genome 
  D) None of the above

Answer 4

A

Question 5

The Tobacco mosaic virus exhibits which type of capsid symmetry? 
  A) Helical 
  B) Icosahedral 
  C) Complex 
  D) None of the above

Answer 5

A

Question 6

An example of a virus that exhibits binal symmetry is known as 
  A) Poxviruses 
  B) Bacteriophages 
  C) Adenoviruses 
  D) Tobacco mosaic virus

Answer 6

B

Question 7

Viral spikes or peplomers are involved in 
  A) Replication 
  B) Lysis 
  C) Attachment 
  D) All of the above

Answer 7

C

Question 8

Which of the following structures are associated with the influenza virus? 
  A) Neuraminidase enzyme 
  B) Hemagglutinin protein 
  C) Glycoproteins 
  D) All of the above

Answer 8

D

Question 9

The most common viral nucleic acid types are 
  A) dsDNA and ssRNA 
  B) dsDNA and dsRNA 
  C) ssDNA and ssRNA 
  D) ssDNA and dsRNA

Answer 9

A

Question 10

The first step in the generalized viral life cycle is
A) Release of virions
B) Self-assembly of virions
C) Synthesis of viral proteins and nucleic acids
D) Attachment of virus to host cell

Answer 10

D

Question 11

Viral host specificity is most likely attributed to
A) The type of genetic material
B) The type of capsid present
C) Random interactions with the host cell
D) Interaction between receptors on the surface of the host cell and ligands on the surface of virions

Answer 11

D

Question 12

Eukaryotic viruses enter host cells through which of the following mechanisms?
A) Fusion of the viral envelope with the host cell membrane
B) Entry by endocytosis
C) Injection of nucleic acid
D) All of the above

Answer 12

D

Question 13

Which types of viruses must carry their own replication enzymes in their nucleocapsid? 
  A) DNA viruses only 
  B) RNA viruses only 
  C) Both DNA and RNA 
  D) Neither DNA nor RNA

Answer 13

B

Question 14

The energy that is required for bacteriophage assembly comes from 
  A) Viral mitochondria 
  B) Viral enzymes 
  C) Host metabolic activity 
  D) All of the above

Answer 14

C

Question 15

A common virion release method observed in enveloped viruses is
A) Lysing of cells at the end of the intracellular phase
B) Movement through pores in the plasma membrane
C) Budding
D) Exocytosis

Answer 15

C

Question 16

The relationship with the host cell in which the virus remains within the host without destroying it is called 
  A) Eclipse 
  B) Lysogeny 
  C) Lytic 
  D) Fundamental

Answer 16

B

Question 17

An advantage of lysogeny to the host includes
A) Resistance to superinfection
B) Ability to lyse virions rapidly
C) Ability to infect new cells quickly
D) All of the above

Answer 17

A

Question 18

When more phage are present in the environment than there are host cells, which type of host relationship is most desirable?
A) Lytic preferred
B) Lysogenic preferred
C) Either lytic or lysogenic, no preference
D) Neither lytic nor lysogenic

Answer 18

B

Question 19

Microscopic and/or macroscopic damages to host cells caused by eukaryotic viruses are called 
  A) Lysis 
  B) Lysogeny 
  C) Cytopathic effects 
  D) None of the above

Answer 19

C

Question 20

A type of viral infection in which there is a slow release of virions without cell death is called 
  A) Acute infection 
  B) Latent infection 
  C) Chronic infection 
  D) Transformation into malignancy

Answer 20

C

Question 21

Cellular genes required for normal growth, but when mutated or overexpressed, cause carcinogenesis are called 
  A) Operons 
  B) Proto-oncogenes 
  C) Transformative genes 
  D) None of the above

Answer 21

B

Question 22

Which one of the following viruses is not definitely linked to causing cancer in humans? 
  A) Rabies virus 
  B) Herpesvirus 
  C) Hepatitis B 
  D) Human papillomavirus

Answer 22

A

Question 23

Which of the following methods can be used to cultivate plant viruses?
A) Grown in cultures of plant cells lacking cell walls
B) Mechanically breaking leaves to expose cells to infection
C) Grafting diseased parts onto a healthy plant
D) All of the above

Answer 23

D

Question 24

_______________________ can be used to determine direct counts of viral particles
A) Bright-field microscopy
B) Epifluorescence microscopy
C) Growth of viral-only cultures on a Petri dish
D) All of the above

Answer 24

B

Question 25

Which of the following is an indirect method of counting animal viruses?
A) Quantitative-polymerase chain reaction (PCR)
B) Counting via epifluorescence microscopy
C) Hemagglutination assay
D) All of the above

Answer 25

C

Question 26

The number of plaque-forming units (PFUs) is calculated from a viral plaque assay by
A) Multiplying the number of plaques per volume by the dilution
B) Dividing the number of plaques per volume by the dilution
C) Adding the dilution to the number of plaques per volume
D) Subtracting the dilution from the number of plaques per volume

Answer 26

A

Question 27

The dilution that contains the number of viral cells large enough to destroy 50% of the host cells or organisms is called 
  A) The infectious dose 
  B) The lethal dose 
  C) The hemagglutination titer 
  D) The dilution response

Answer 27

B

Question 28

Infectious RNAs that primarily infect plants are called 
  A) Viral-like particles 
  B) Viroids 
  C) Virusoids 
  D) Prions

Answer 28

B

Question 29

Infectious proteins responsible for bovine spongiform encephalopathy are called 
  A) Viral-like particles 
  B) Viroids 
  C) Virusoids 
  D) Prions

Answer 29

D