Deck 5: Viruses and Viral Diseases

Question 1

A virus that specifically attacks bacteria is called a

A)virion.
B)provirus.
C)plasmid.
D)phage.
E)prion.

Answer 1

D

Question 2

A prion is

A)a type of virus which causes neurodegenerative diseases in humans and animals.
B)an infective protein that causes encephalitis.
C)easily destroyed by most disinfectants.
D)responsible for infections in animals but not humans.
E)easily transmissible from person to person.

Answer 2

B

Question 3

A virus that exhibits tissue tropism

A)infects one or a limited number of tissue types.
B)attaches to numerous cell types,but only infects one type.
C)is always able to cross the species barrier.
D)is resistant to host defence mechanisms in that tissue.
E)always causes life-threatening infections.

Answer 3

A

Question 4

Place the steps of viral multiplication in an animal cell into the correct order.
[key: 1 = release,2 = maturation,3 = adsorption,4 = uncoating,5 = penetration,6 = biosynthesis]

A)1,2,3,4,5,6
B)6,5,4,3,2,1
C)6,4,2,3,1,5
D)3,5,4,6,2,1
E)3,4,5,6,1,2

Question 5

To see the structure of viruses,it is necessary to use

A)a light microscope.
B)a phase contrast microscope.
C)an inverted microscope.
D)an electron microscope.
E)viruses are too small to be seen.

Question 6

Which of the following is TRUE?

A)Viruses that infect humans never infect other animals.
B)All viruses can only attack one type of cell.
C)Each virus attaches to a specific receptor site on its target cells.
D)Viruses that infect birds do not infect humans.
E)All of the above.

Question 7

Which of the following bacteria contain a phage which is responsible for its virulence?

A)Corynebacterium diphtheria.
B)Bordetella pertussis.
C)Clostridium tetani.
D)Mycobacterium tuberculosis.
E)None of the above because bacteria don't need a phage for virulence.

Question 8

During viral infection in human cells the

A)virus attaches to the host cell and injects its nucleic acid into the cell.
B)protein capsid of the virus is digested by lysozyme.
C)viral nucleic acid is copied by the host cell DNA.
D)viral DNA directs the host cell DNA to synthesise viral components.
E)host cell is not damaged when the new viral particles are released.

Question 9

Which of the following statements about retroviruses is TRUE?

A)They usually synthesise DNA from viral RNA.
B)They all contain an enzyme called reverse transcriptase.
C)Their replication can be inhibited with nucleotide analogues.
D)The human immunodeficiency virus is a retrovirus.
E)All of the above.

Question 10

Which of the following is TRUE about viruses?

A)They are composed of cells.
B)They metabolise nutrients.
C)They reproduce outside a living cell.
D)They have RNA or DNA.
E)All of the above.

Question 11

Which of the following is produced by the body in response to viral infection?

A)Memory cells.
B)Cytokines.
C)Interferon.
D)Antibodies.
E)All of the above.

Question 12

The nucleic acid present in viruses is

A)single-stranded RNA.
B)double-stranded RNA.
C)single-stranded DNA.
D)double-stranded DNA.
E)any of the above.

Question 13

Hepatitis A,hepatitis B and hepatitis C are viruses which

A)all belong to the same family of viruses.
B)can all be prevented by vaccination.
C)are all mainly transmitted by blood.
D)all affect the liver in humans.
E)all of the above.

Question 14

Viral nucleic acid

A)carries all the information necessary for the replication of new viral particles.
B)codes only for some viral structural proteins and enzymes.
C)acts as a template for synthesis of host cell mRNA.
D)codes for the host cell enzymes required for viral synthesis.
E)codes for the synthesis of interferon.

Question 15

During infection of a bacterial cell by a bacteriophage

A)new phage particles are produced and released when the cell lyses.
B)the phage DNA is incorporated into the host cell DNA and remains dormant.
C)the phage may carry some of the host cell DNA to the next cell it infects.
D)the phage DNA is incorporated into the bacterial chromosome and gives the bacterium new properties.
E)any of the above may occur.

Question 16

The ability of a virus to infect an organism is determined by the

A)host species.
B)type of cell.
C)availability of an attachment site.
D)all of the above.
E)none of the above.

Question 17

Viruses that do not have an envelope are called

A)virions.
B)particles.
C)naked.
D)viroids.
E)prions.

Question 18

The name virus literally means

A)alive.
B)poison.
C)infectious.
D)microscopic.
E)non-living.

Question 19

The viral capsid

A)comprises lipids and proteins in a highly organised structure.
B)gives all viruses the same shape.
C)has a structure that enables viruses to evade human antibodies.
D)enables a single virus to attach to numerous host cell types.
E)is made up of repeated protein units.

Question 20

A virion is

A)a complete, mature virus.
B)a virus that infects only humans.
C)able to be just seen in a light microscope.
D)capable of limited replication outside of cells.
E)all of the above.

Question 21

Oncogenic viruses are ones which

A)can cause cancer.
B)transform cells.
C)integrate their DNA into the host cell genome.
D)suppress contact inhibition in infected cells.
E)all of the above.

Question 22

An example of a virus which can cause congenital defects is

A)mumps virus.
B)polio virus.
C)rubeola virus.
D)rubella virus.
E)none of the above.

Question 23

In a chronic viral infection

A)viruses aren't shed from the body.
B)the person is usually non-contagious.
C)symptoms may be non-existent or mild.
D)the body doesn't produce antibodies against the virus.
E)all of the above.

Question 24

Which of the following viruses is associated with cervical cancer?

A)Hepatitis A virus.
B)Hepatitis B virus.
C)Hepatitis C virus.
D)Human immunodeficiency virus.
E)Human papilloma virus.

Question 25

A virus that is able to cause serious infections in both humans and animals is

A)measles virus.
B)rubella virus.
C)rabies virus.
D)toxoplasma virus.
E)Ross River fever virus.

Question 26

An arbovirus infection is transmitted by

A)trees.
B)birds.
C)insects.
D)reptiles.
E)none of the above.

Question 27

An example of a virus which is transmitted by a mosquito is

A)malaria virus.
B)polio virus.
C)Murray Valley encephalitis virus.
D)cytomegalovirus.
E)coronavirus.

Question 28

A subclinical infection

A)doesn't induce an immune response in the body.
B)can not be transmitted to another person.
C)is caused by viruses with a slow metabolism.
D)does not cause any signs or symptoms in the person.
E)all of the above.

Question 29

Which of the following is NOT a description of a type of viral infection?

A)Latent.
B)Passive.
C)Acute.
D)Oncogenic.
E)Subclinical.

Question 30

Which of the following could be a symptom of a viral infection?

A)Fever.
B)Lymphadenopathy.
C)Rash.
D)Pruritus.
E)Any of the above.

Question 31

Hepatitis B virus can cause a carrier state in a person,which means that

A)there is a continuous,low level of virus replication.
B)the person is infected but doesn't transmit the virus.
C)the infection will only ever be mild.
D)the person's immune system is permanently damaged.
E)all of the above.

Question 32

Some viruses are associated with the development of cancer.An important characteristic of cancer cells is

A)the lack of contact inhibition.
B)the inability to synthesise protein.
C)the slow metabolism.
D)no nuclear membrane.
E)the lack of staining properties.

Question 33

Which of the following is a characteristic of a latent viral infection?

A)There may be no obvious clinical signs or symptoms.
B)The virus is dormant in a cell and can be re-activated.
C)The patient may develop a related disease if they become immunocompromised.
D)The patient may or may not be infectious.
E)All of the above.

Question 34

Which of the following has been associated with a form of human liver cancer?

A)Human papilloma virus.
B)Hepatitis B virus.
C)Herpes zoster virus.
D)Hepatitis A virus.
E)Human immunodeficiency virus.

Question 35

Which of the following causes a latent infection?

A)Herpes zoster virus.
B)Poliovirus.
C)The common cold virus.
D)Influenza virus.
E)Rubella virus.

Question 36

Which of the following viruses is commonly transmitted by the faecal-oral route?

A)Norovirus.
B)Hepatitis A virus.
C)Polio virus.
D)Rotavirus.
E)All of the above.

Question 37

The presence of viruses in a person's bloodstream is a

A)viraemia.
B)fatal infection.
C)lytic infection.
D)virulent.
E)virosis.

Question 38

The outbreak of a new strain of influenza that occurs each year is due to

A)a lack of antiviral drugs.
B)climatic conditions which activate the virus.
C)a lack of influenza vaccine.
D)mutations in the influenza virus.
E)global travel.

Question 39

Influenza A virus is able to cause infections year after year because

A)it infects different cell types each time.
B)the body's immune system doesn't respond to it.
C)it mutates regularly,changing its outer structures.
D)each year a new influenza virus crosses from birds to humans.
E)all of the above.

Question 40

Viruses which can cause transformation of normal cells into tumour cells are called

A)persistent.
B)latent.
C)pathogenic.
D)oncogenic.
E)mutant.

Question 41

Which of the following viral infections has been eradicated from the world by vaccination?

A)Polio.
B)Smallpox.
C)Whooping cough.
D)Measles.
E)Mumps.

Question 42

Cytopathic effects (CPE)are changes in cells due to

A)viral infections.
B)a lack of immune response.
C)bacterial infections.
D)a lack of oxygen.
E)all of the above.

Question 43

Interferons are

A)antiviral substances produced in response to viral infection.
B)proteins that transmit infection from one cell to another.
C)substances that transform cancer cells.
D)synthetic drugs that are used to treat bacterial infections.
E)substances that interfere with antibody formation.

Question 44

The major reason we have relatively few antiviral drugs is that

A)viruses are resistant to most chemicals.
B)viruses use host cell mechanisms to replicate.
C)viruses don't have any enzymes to attack.
D)viruses don't have a cell wall.
E)all of the above.

Question 45

Which of the following is NOT a method of culturing viruses?

A)In laboratory animals.
B)In cell culture.
C)In embryonated eggs.
D)On an agar plate.
E)All of the above can be used to culture viruses.