Chapter 5_8 Viruses
1) Which of these comprises the viral genome?
a) single-stranded DNA
b) single-stranded RNA
c) double-stranded DNA
d) double-stranded RNA
e) All of these choices are seen in viruses.
2) What is the viral capsid composed of?
a) protein
b) nucleic acid
c) lipid
d) polysaccharide
e) glycogen
8) Viruses that have icosahedral symmetry have ________ faces and 12 vertices resulting in a
spherical appearance.
a) 10
b) 20
c) 30
d) 40
e) 50
9) Enveloped viruses are mainly associated with which of the following?
a) plants and bacteria
b) animals
c) bacteria
d) plant and animals
e) plants
10) What is the first step in the viral replication cycle?
a) RNA synthesis
b) genome synthesis
c) entry into the cell
d) attachment to the cell
e) viral RNA translation
12) What is the most common way for enveloped viruses to enter animal cells?
a) The virion fuses itself to the cell membrane.
b) The virion directly injects its nucleic acid.
c) Endocytosis of the virion.
d) Through lysis of the cell.
e) Via a hole in the cell membrane.
14) How do bacteriophages invade the bacteria cell?
a) The bacteriophage fuses itself to the cell membrane.
b) The bacteriophage directly injects its nucleic acid.
c) Endocytosis of the bacteriophage.
d) Through lysis of the cell.
e) Via a hole in the cell membrane.
16) Many enveloped viruses exit their host cell through a process called _________.
a) exocytosis
b) budding
c) cell lysis
d) receptor-mediated endocytosis
e) phagocytosis
18) What is the premise of the progressive hypothesis of viral origin?
a) Viruses evolved from symbionts of cells.
b) Viruses evolved from self-replicating nucleic acid segments.
c) Viruses originated from cells that lost the ability to replicate.
d) Viruses were present when the first primordial cells evolved.
e) Viruses arose from fragmented DNA in a cell.
21) The term for bacteriophage DNA that has integrated into the host cell chromosome and
replicates along with the host cell chromosome.
a) a plasmid
b) a transposon
c) a prophage
d) a lysogen
e) a retrophage
32) How do prions cause disease?
a) By corrupting mRNA expression in the cell.
b) By corrupting DNA replication in the cell.
c) By preventing translation from occurring in the cell.
d) By causing naturally occurring proteins in the cell to change shape.
e) By preventing proper RNA transcription termination.
1) Most likely, “host specificity” of a virus is determined by
a) the type of nucleic acid it contains.
b) the presence or absence of an envelope.
c) viral enzymes.
d) interactions between viral attachment proteins and host cell receptors.
e) viral nucleic acid replication strategies.
2) The viral attachment protein specifically binds to a host cell receptor. All of the following
are examples of known host cell receptors except
a) DNA.
b) proteins.
c) glycoproteins.
d) lipopolysaccharides.
e) sialic acids.
3) The ability of a virus or bacteriophage to specifically attach to a host cell occurs through
the interactions of the viral attachment protein with the host cell receptor. This binding
determines
a) the rate of viral replication.
b) the host range.
c) the mechanism of viral entry.
d) whether or not the virus will contain an envelope.
e) the rate of viral RNA replication.
6) Antiviral drugs that act at the level of host recognition are designed to
a) prevent endocytotic vesicle formation.
b) prevent virus binding to the host cell receptor.
c) enhance antibody production.
d) inactivate viral nucleic acid polymerases.
e) bind to viral metabolic enzymes.
8) HIV enters the cell through a/an _________ mechanism.
a) phagocytic
b) receptor-mediated endocytotic
c) membrane fusion
d) acid-dependent endosomal
e) receptor-independent endocytotic
9) The influenza virus gains entry into a host cell by
a) direct injection of its nucleic acid.
b) receptor-independent endocytosis.
c) lysis of the cell membrane.
d) receptor-mediated endocytosis.
e) pinocytosis.
10) The influenza virus gains entry into a host cell by an endocytotic process. The viral
nucleocapsid leaves the endosome and enters the cytoplasm through a membrane fusion
mechanism. Fusion of the viral envelope with the endosomal membrane is facilitated by
a) a conformation change in the hemagglutinin to expose a fusion protein.
b) the production of a lipase by the influenza virus.
c) sialic acid residues of the receptor proteins.
d) specific viral protein recognition of pores in the endosome vesicle.
e) the production of proteases by the influenza virus.
21) For most double-stranded DNA eukaryal viruses, DNA replication occurs in the _________
and translation occurs in the __________.
a) cytoplasm, cytoplasm
b) cytoplasm, nucleus
c) nucleus, nucleus
d) nucleus, cytoplasm
e) mitochondria, cytoplasm
22) Most RNA viruses utilize
a) an RNA-dependent RNA polymerase.
b) a DNA-dependent RNA polymerase.
c) an RNA-dependent DNA polymerase.
d) a DNA-dependent DNA polymerase.
e) reverse transcriptase.
31) Many antiviral drugs are nucleoside analogs. The nucleoside analogs primarily target
these enzymes
a) host cell DNA polymerases.
b) host cell RNA polymerases.
c) host cell nucleases.
d) viral nucleic acid polymerases.
e) viral nucleases.
32) The reason nucleoside analogs are effective against viral nucleic acid polymerases is
because
a) viral polymerases have a very high rates of polymerization.
b) viral polymerases have a low rate of polymerization.
c) viral polymerases have a high affinity for incorporation of the analogs.
d) viral polymerase activity is inhibited by the analogs.
e) viral polymerase activity is enhanced by the analogs.
33) AZT is a nucleotide analog used to treat people infected with
a) herpes virus.
b) HIV.
c) papilloma virus.
d) influenza virus.
e) polio virus.
10.
A key factor in the evolution of killer strains of influenza is that it
A. only has 8 genes.
B. has an RNA genome.
C. contains reverse transcriptase.
D. has a segmented genome.
E. has a circular chromosome.
7. Which of the following best describes the genome of influenza virus?
A. negative strand segmented RNA
B. positive strand segmented RNA
C. negative strand single-piece RNA
D. positive strand single-piece RNA
E. double-stranded RNA
12. The nucleocapsid of an enveloped virus was found to have 20 capsomers per
face. How many capsomers total are there in each particle?
A. 200
B. About
C. 400
D. About
E.
One
particles
2000
4000
can’t say, because the envelope
of any particular enveloped virus.
size
varies
substantially
for
6. 5'-CTAAGCGG-3' is part of a virus's ssDNA(+) genome. Imagine that this
genome is converted to the ssDNA(-) during the infectious cycle. Write the
ssDNA(-) equivalent of the above sequence-be sure to label 5' and 3' ends.
17. In the biology of influenza, what is responsible for the phenomenon of
"antigenic drift"?
18a. If antigenic drift were to suddenly disappear, would flu vaccinations
still be required every year? Why or why not?
1. Starting with binding to the host cell surface, draw the
infection cycle of influenza A. End with virus release from
the host, and be sure to include synthesis of viral mRNA and
viral proteins.
14. In class we discussed virus from the Herpes family.
that family have in common?
What do viruses in
A. Infection with any family member always results in serious symptoms
B. They all have dsDNA genomes
C.
They all reside as latent particles in the host and can cause disease
symptoms long after the initial infection
D. Two of the above are correct
E. Three of the above are correct
------15.
Which of the diseases listed below is not a result of infection by a
member of the Herpes family?
A. Cold sores
B. Shingles
C. Chicken pox
D. Roseola (also known as sixth disease)
E. All of the above are caused by Herpes viruses
------16.
In class we discussed viral hepatitis. Which statement about viral
hepatitis is not true.
A. It is always caused by enveloped viruses with ssDNA genomes
B. It is an infection of the liver
C. It is can passed by blood or intimate contact
D. It can be deadly
E. It can be mild
------17.
HIV is a retrovirus, and many of the earliest anti-HIV drugs targeted
reverse transcriptase. What does reverse transcriptase do?
A. Make DNA, using RNA
B. Make ssRNA(+) using
C. Make ssRNA(-) using
D. Make RNA, using DNA
E. All of the above
------18.
A.
B.
C.
D.
E.
as template
ssRNA(-) as a template
ssRNA(+) as a template
as template
Which of the following molecules act as a host-cell receptor for HIV?
CD4
CCR5
AIDS docking complex
CD4 and CCR5
AIDS docking complex and CCR5
21.
Consider the following segment of ssRNA(-): 5'-GUUAACGGCA-3' .
would be the linear sequence of its corresponding ssRNA(+) version?
A.
B.
C.
D.
E.
What
5’-CAAUUGCCGU-3’
3’-GUUAACGGCA-5’
5'-GUUAACGGCA-3'
3’-CAAUUGCCGU-5’
5’-None of the above-3’
23. Once infected with Herpes Simplex 1 (HSV1) cold-sores tend to reappear
in the same place on a regular basis. Why?
A. Because cold sores tend to reappear when lips become dry and chapped
during winter.
B. Because the cells at that site have many viral receptors after the
initial infection
C. Because the virus makes the site inaccessible to the immune system, and
the site is then unprotected and open to re-infection
D. Because the virus takes up residence in nerve ganglions and follows
nerves back to the site of infection
28.
Which of the following statements about Hepatitis B virus and HIV are
true?
A. Both have genomes consisting of DNA.
B. Both are transmitted by the similar types of "lifestyle practices"
C. Neither is problematic in developed countries
D. Effective vaccinations are currently available for both.
E. None of the statements are true
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