Deck 6: An Introduction to Viruses

Question 1

Which of the following represents a virus family name?

A)Herpes simplex virus
B)Herpesviridae
C)Picornavirus
D)Enterovirus
E)Hepatitis B virus

Answer 1

B

Question 2

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

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

Answer 2

D

Question 3

These 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.

Answer 3

B

Question 4

All of the following pertain to virus envelopes except they

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

Question 5

Which of the following is not associated with every virus?

A)envelope
B)capsomers
C)capsid
D)nucleic acid
E)genome

Question 6

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)blood agar

Question 7

Which 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 8

The correct sequence of events in viral multiplication is

A)penetration, replication, maturation, adsorption, assembly, release.
B)replication, penetration, maturation, assembly, absorption, release.
C)adsorption, penetration, replication, maturation, assembly, release.
D)assembly, maturation, replication, release, penetration, adsorption.
E)adsorption, release, maturation, replication, assembly, penetration.

Question 9

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 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 10

Viruses acquire envelopes around their nucleocapsids during

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

Question 11

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.

Question 12

Virus capsids are made from subunits called

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

Question 13

Which of the following is correct about viruses?

A)cannot be seen with a light microscope
B)are prokaryotic
C)contain 70S ribosomes
D)undergo binary fission
E)can be grown on nutrient agar

Question 14

The core of every virus particle always contains

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

Question 15

Viruses have all the following except

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

Question 16

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

Question 17

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

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

Question 18

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 19

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 20

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.

Question 21

When a virus enters a lysogenic phase, it means

A)the virus is integrated into the DNA of the host cell and is latent.
B)the virus is bursting through the host cell membrane.
C)the virus is starting biosynthesis of its nucleic acid.
D)the virus will remain in circulation and not continue infecting its host.
E)the number of viruses in the host is decreasing as the immune system becomes effective.

Question 22

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.

Question 23

Oncogenic viruses include all the following except

A)Hepatitis B virus.
B)Measles virus.
C)Papillomavirus.
D)HTLVI and HTLVII viruses.
E)Epstein-Barr virus.

Question 24

The capsomers are made of

A)DNA.
B)RNA.
C)lipids.
D)protein.
E)carbohydrate.

Question 25

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

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

Question 26

Infectious protein particles are called

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

Question 27

Viruses belong to which of the following Kingdoms?

A)Protists
B)Fungi
C)Archaea
D)Bacteria
E)None of the choices are correct.

Question 28

Viruses that consist of only a nucleocapsid are considered

A)simple viruses.
B)complex viruses.
C)naked viruses.
D)viroids.
E)incomplete viruses.

Question 29

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.

Question 30

Creutzfeld-Jacob 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 31

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

A)Rabies
B)Smallpox
C)Tobacco Mosaic Virus
D)Herpes
E)Epstein-Barr virus

Question 32

Infectious naked strands of RNA are called

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

Question 33

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 34

All of the following is correct about treating viral diseases except

A)viruses are killed by the same antibiotics that kill bacteria.
B)many antiviral drugs block viral replication.
C)many antiviral drugs cause severe side effects.
D)interferons show potential for treating and preventing viral infections.
E)All of the choices are correct.

Question 35

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

A)envelope
B)nucleic acid
C)capsid
D)capsomers
E)None of the choices are optional parts of a virus.

Question 36

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

A)digestive
B)genitourinary
C)nervous
D)circulatory
E)respiratory

Question 37

The nucleocapsid consists of

A)the capsomers assembled into the capsid.
B)the nucleic acid of the virus only.
C)the nucleic acid along with the capsid.
D)the envelope and capsid.
E)the envelope, nucleic acid, and capsid.

Question 38

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 39

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.

Question 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.

Question 41

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

Question 42

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

Question 43

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

Question 44

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.

Question 45

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

Question 46

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

Question 47

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

Question 48

Viruses that infect bacteria are specifically called _____.

Question 49

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

Question 50

Spikes are glycoproteins of the virus capsid.

Question 51

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

Question 52

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

A)Lytic phase
B)Budding
C)Adsorption
D)Lysogenic conversion
E)Latent phase

Question 53

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

Question 54

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

Question 55

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

Question 56

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

Question 57

How do enveloped animal viruses exit their host?

A)Budding or exocytosis
B)Bursting the host cell
C)Rupturing the virus
D)Endocytosis
E)None of these are correct

Question 58

Viral infections are easier to treat with drugs than bacterial infections.

Question 59

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

Question 60

A naked virus does not have a(n) _____.

Question 61

Compare and contrast the steps of viral multiplication cycles in bacteriophages and animal viruses.

Question 62

Compare and contrast viruses, prions, and viroids.

Question 63

Discuss at least six characteristics that are unique to viruses compared to other microorganisms.

Question 64

Discuss why it is difficult to trace the origins of viruses and why they are important.

Question 65

Explain what is meant by host range, what governs host range, and what is meant by tissue tropism.

Question 66

Discuss the criteria used for classifying viruses into families and genera.

Question 67

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

Question 68

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