Deck 5: Viral Structure and Multiplication

Question 1

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

Answer 1

A

Question 2

Who developed a rabies vaccine by separating bacteria from virus using a filter?

A)Leeuwenhoek
B)Koch
C)Pasteur
D)Cohn
E)Semmelwise

Answer 2

C

Question 3

A(n)________ is the protein shell around the nucleic acid core of a virus.

A)capsomere
B)capsid
C)spike
D)envelope
E)monolayer

Answer 3

B

Question 4

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

Question 5

Viruses acquire envelopes around their nucleocapsids during ________.

A)replication
B)assembly
C)adsorption
D)release
E)penetration

Question 6

Reverse transcriptase synthesizes ________.

A)the positive RNA strand from a negative RNA strand
B)a negative RNA strand from a positive RNA strand
C)RNA from DNA
D)DNA from RNA
E)None of the choices are correct

Question 7

One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a(n)________ capsid.

A)spiked
B)complex
C)icosahedral
D)helical
E)buckeyball

Question 8

A naked virus has only a(n)________.

A)capsid
B)capsomere
C)nucleocapsid
D)envelope
E)antigenic surface

Question 9

Virus capsids are made from subunits called ________.

A)envelopes
B)spikes
C)capsomeres
D)prophages
E)peplomers

Question 10

Viruses have all the following except ________.

A)definite shape
B)metabolism
C)genes
D)the ability to infect host cells
E)ultramicroscopic size

Question 11

Which of the following is not a typical capsid shape?

A)Tetrahedral
B)Complex
C)Helical
D)Icosahedron
E)All of the choices are capsid shapes.

Question 12

The core of every virus particle always contains ________.

A)DNA
B)capsomeres
C)enzymes
D)DNA and RNA
E)either DNA or RNA

Question 13

A negative-sense RNA virus ________.

A)is ready for immediate translation
B)must synthesize a negative RNA copy of its genome
C)must synthesize a positive RNA copy of its genome
D)is a special form of tRNA used by viruses
E)always codes for RNA polymerase

Question 14

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)None of the choices are correct

Question 15

Viruses ________.

A)cannot be seen in a light microscope
B)are prokaryotic
C)contain 70S ribosomes
D)undergo binary fission
E)All of the choices are correct

Question 16

Which of the following is not associated with every virus?

A)Envelope
B)Capsomeres
C)Capsid
D)Nucleic acid
E)Genome

Question 17

Viral nucleic acids 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

Question 18

All of the following pertain to virus envelopes except ________.

A)gained as a virus leaves the host cell membrane
B)are comprised primarily of lipids
C)contain special virus proteins
D)help the virus particle attach to host cells
E)are located between the capsid and nucleic acid

Question 19

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

A)spike
B)capsomere
C)envelope
D)capsid
E)core

Question 20

Viral spikes ________.

A)are present on all viruses
B)protrude from the envelope
C)block attachment between virus and host
D)are derived from host proteins
E)All of the choices are correct

Question 21

New,nonenveloped virus release occurs by ________.

A)lysis
B)budding
C)exocytosis
D)both lysis and budding
E)both budding and exocytosis

Question 22

T-even phages ________.

A)include the poxviruses
B)infect Escherichia coli cells
C)enter host cells by engulfment
D)have helical capsids
E)All of the choices are correct

Question 23

Host range is limited by ________.

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
E)All of the choices are correct

Question 24

Mammalian viruses capable of starting tumors are ________.

A)chronic latent viruses
B)oncoviruses
C)syncytia
D)inclusion bodies
E)cytopathic

Question 25

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

Question 26

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

Question 27

Which of the following occurs during assembly of an enveloped virus?

A)Nucleocapsid is formed.
B)New viral nucleic acid is formed.
C)Viral spikes insert in host cell membrane.
D)A nucleocapsid is formed and viral spikes insert in host cell membrane.
E)All of the choices occur.

Question 28

Lysogeny refers to ________.

A)altering the host range of a virus
B)latent state of herpes infections
C)virion exiting host cell
D)viral genome inserting into bacterial host chromosome
E)None of the choices are correct

Question 29

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

Question 30

Persistent viruses that can reactivate periodically are ________.

A)chronic latent viruses
B)oncoviruses
C)syncytia
D)inclusion bodies
E)cytopathic

Question 31

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)None of the choices are correct

Question 32

Viruses attach to their hosts via ________.

A)host glycoproteins
B)host phospholipids
C)viral phospholipids
D)viral flagella
E)All of the choices are correct

Question 33

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 change shape
E)All of the choices are correct.

Question 34

Viruses that infect bacteria are specifically called ________.

A)viroids
B)prions
C)bacteriophages
D)satellite viruses
E)All of the choices infect bacteria.

Question 35

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

Question 36

Uncoating of viral nucleic acid ________.

A)does not occur in bacteriophage multiplication
B)involves enzymatic destruction of the capsid
C)releases viral nucleic acid into the cell
D)occurs before replication
E)All of the choices are correct

Question 37

Oncoviruses include all the following except ________.

A)hepatitis B virus
B)measles virus
C)papillomavirus
D)HTLV I
E)Epstein-Barr virus

Question 38

What structures are used by bacteriophages to attach to host cell receptors?

A)Sheath
B)Tail fibers
C)Nucleic acid
D)Capsid head
E)None of the choices are correct

Question 39

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

Question 40

Viral tissue specificities are called ________.

A)ranges
B)virions
C)receptacles
D)tropisms
E)uncoating

Question 41

A fully formed virus that can cause an infection in a host cell is called a virion.

Question 42

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

Question 43

Satellite viruses are ________.

A)also called viroids
B)dependent on other viruses for replication
C)the cause of spongiform encephalopathies
D)significant pathogens of plants
E)All of the choices are correct

Question 44

The activation of a prophage is called ________.

A)activation
B)lysogeny
C)transformation
D)induction
E)adsorption

Question 45

Infectious naked strands of RNA that affect plants are called ________.

A)viroids
B)phages
C)prions
D)oncogenic viruses
E)spikes

Question 46

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

A)embryo
B)cell
C)plaque
D)bacteriophage
E)egg

Question 47

Creutzfeldt-Jakob disease is ________.

A)caused by a chronic latent virus
B)initiated by an oncogenic virus
C)caused by a viroid
D)a spongiform encephalopathy of humans
E)also called "mad cow disease"

Question 48

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

Question 49

What type of phage enters an inactive prophage stage?

A)Primary
B)Secondary
C)Temperate
D)Temporary
E)Transformed

Question 50

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

A)prions; capsomeres
B)virions; prions
C)viroids; phages
D)prions; phages
E)prions; viroids

Question 51

The development of antiviral drug therapy is difficult because ________.

A)viruses are obligate intracellular parasites so the host cell can be harmed by the drug
B)viruses do not have specific replication cycles that can be targeted
C)viruses do not contain genetic material
D)their life cycles do not have distinctive stages

Question 52

Cells grown in culture form a(n)________.

A)monolayer
B)bilayer
C)aggregate
D)plaque
E)None of the choices are correct.

Question 53

Spikes are glycoproteins of the virus capsid.

Question 54

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

Question 55

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

Question 56

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.

Question 57

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

A)lysogeny
B)budding
C)plaques
D)cytopathic effects
E)pocks

Question 58

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

A)host cytoplasm
B)host nucleus
C)host nucleolus
D)host DNA
E)host cell membrane

Question 59

The primary purpose of viral cultivation is ________.

A)to isolate and identify viruses in clinical specimens
B)to prepare viruses for vaccines
C)to do detailed research on viral structure,lifestyle,genetics,and effects on host cells
D)All of the choices are correct

Question 60

Infectious protein particles are called ________.

A)viroids
B)phages
C)prions
D)oncogenic viruses
E)spikes

Question 61

An ideal antiviral drug would be one that killed the host cell,effectively preventing the virus from replicating.

Question 62

Glycoprotein spikes are essential for mediating the release stage of the viral life cycle.

Question 63

Viruses are the most common cause of acute infections that do not result in hospitalization.

Question 64

A specific animal virus has the ability to attach to and enter almost any animal host cell.

Question 65

Viruses mutate and some have not been discovered.

Question 66

A patient undergoing chemotherapy for cancer develops an infection with cytomegalovirus,conclusively diagnosed by the presence of "owl's eye" viral nuclear inclusions in a liver biopsy.  This is an example of a(n) ________.

A)cytopathic effect by cytomegalovirus
B)immune response by the host
C)cytomegalovirus becoming a provirus
D)transformation of the host cell by cytomegalovirus

Question 67

Respiratory syncytial virus (RSV)is a common respiratory virus that causes mild cold-like symptoms in most individuals,but can be more serious in infants and the elderly.RSV is so-named because ________.

A)it causes the fusion of damaged host cells,forming a large,multinucleated cell
B)it causes the proliferation of inclusion bodies within the host cell
C)it causes a persistent infection in the host
D)it transforms the host cell,causing cancer

Question 68

The adeno-associated virus (AAV)is a prion.

Question 69

Viral spikes are inserted into the host cell membrane before budding or exocytosis.

Question 70

The patient asks the RN how she contracted this viral infection since she has not come in contact with anyone with anyone infected with shingles.Which of the following statements is an appropriate response?

A)Varicella zoster virus can remain in a chronic latent state by integrating into a bacteriophage.
B)Varicella zoster virus can remain in a chronic latent state by turning on oncogenes.
C)Varicella zoster virus can remain in a chronic latent state by attacking T cells.
D)Varicella zoster virus can hide from the immune system within nerve cells.

Question 71

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

Question 72

Viruses are simple,noncellular,and lack ribosomes.

Question 73

Viruses are not filterable.

Question 74

Which of the following is not true regarding the structure and function of viral spikes?

A)They are found on both enveloped and naked viruses
B)They are coded for by the host genome
C)They are coded for by the viral genome
D)They mediate the docking process of virus to host cell
E)They consist of proteins and carbohydrates

Question 75

An ideal antiviral drug would be one that ________.

A)disrupted an integral viral process while causing little damage to the host cell
B)killed the host cell thereby depriving the virus of its means to translate proteins
C)killed both the virus and the host cell
D)prevents translation by the host cell ribosome,depriving the virus of a means to replicate

Question 76

It is necessary to culture viruses both in vivo and in vitro so that vaccines can be developed,analysis of viral genomes can be made and viruses in clinical specimens can be identified.

Question 77

Viruses contain the necessary tools to invade and control a host cell.These tools may consist of a ________.

A)nucleus,nucleic acid strands of DNA and RNA,and enzymes
B)capsid or envelope,nucleic acid strands of DNA or RNA,and enzymes
C)nucleus,nucleic acid strands of RNA,capsid,and enzymes
D)capsid or envelope,nucleic acid strands of DNA,and enzymes

Question 78

Viral genetic studies,vaccine development and clinical identification would not be possible without the ability to ________.

A)culture viruses in vivo and in vitro
B)transform human cells into cancerous cells
C)studying prions in neurological tissue of animals
D)activate lysogenic induction in bacteriophages

Question 79

You are running an experiment in calf serum,which cannot be autoclaved because proteins essential to your protocol will be denatured.  You decide to filter sterilize the serum since the 0.22μm filter is small enough to block any bacteria that may contaminate your tissue culture.  The success of this procedure hinges on the fact that ________.

A)the presence of viruses in your serum is inconsequential to your experiment
B)some of the bacteria will still be allowed to filter through
C)viruses,as well as bacteria,will also be blocked by the 0.22μm pore size
D)the proteins in the serum are also blocked by the pore size

Question 80

Viruses are unable to multiply outside of a host cell.