BIOL 271 Microbiology w/ Lab Module 6 Exam Review v2.0: Advanced Virology, Viral
Pathogenesis Mechanisms, Antiviral Pharmacology, and Diagnostic Interpretation for Portage
Learning LockDown Browser Comprehensive Assessment
SECTION 1: VIRAL STRUCTURE, CLASSIFICATION, AND GENOME DIVERSITY (Questions 1-25)
🟢 1. A novel virus is isolated from a thermal vent archaeon. Structural analysis reveals a lipid monolayer surrounding the capsid rather than a bilayer. This
unique envelope structure is most likely derived from:
A. The host archaeal plasma membrane, which contains ether-linked lipids forming a monolayer
B. The nuclear membrane of the host cell
C. A unique viral-encoded lipid synthesis pathway
D. The endoplasmic reticulum of the host cell
<span style="color:red;border:1px solid red;padding:2px 6px;">A. The host archaeal plasma membrane, which contains ether-linked lipids
forming a monolayer</span>
Rationale: Archaeal membranes are composed of ether-linked lipids that form a monolayer rather than the phospholipid bilayer found in bacterial and
eukaryotic membranes. Viruses that infect archaea acquire envelopes from the host membrane.
🟢 2. A virologist determines that a newly discovered virus has a genome consisting of 12,000 nucleotides of positive-sense single-stranded RNA with a 5'
cap and 3' polyadenylated tail. Based on this information, which of the following statements is MOST accurate regarding the virus's replication strategy?
A. The viral genome must first be converted to double-stranded DNA by reverse transcriptase
B. The viral genome cannot be translated until it is replicated by viral RNA-dependent RNA polymerase
C. The viral genome can be directly translated by host ribosomes to produce viral polyproteins
D. The viral genome requires host DNA-dependent RNA polymerase for transcription
<span style="color:red;border:1px solid red;padding:2px 6px;">C. The viral genome can be directly translated by host ribosomes to
produce viral polyproteins</span>
Rationale: Positive-sense single-stranded RNA viruses have genomes that function as mRNA. The presence of a 5' cap and 3' poly(A) tail indicates that the
genome is ready for translation by host ribosomes.
🟢 3. Which of the following correctly describes the Baltimore classification group that includes viruses with a negative-sense single-stranded RNA
genome?
A. Group III: dsRNA viruses
B. Group IV: positive-sense ssRNA viruses
C. Group V: negative-sense ssRNA viruses
D. Group VI: ssRNA-RT viruses
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Group V: negative-sense ssRNA viruses</span>
Rationale: The Baltimore classification groups viruses based on their genome type and replication strategy. Group V includes viruses with negative-sense
single-stranded RNA genomes (e.g., Ebola, influenza, rabies).
🟢 4. A bacteriophage is observed to have an icosahedral head, a contractile tail sheath, and tail fibers. This phage is BEST classified as a member of the:
,A. Myoviridae family (contractile tails)
B. Siphoviridae family (long non-contractile tails)
C. Podoviridae family (short tails)
D. Inoviridae family (filamentous)
<span style="color:red;border:1px solid red;padding:2px 6px;">A. Myoviridae family (contractile tails)</span>
Rationale: Bacteriophages are classified into families based on tail morphology. Myoviridae have contractile tails, Siphoviridae have long non-contractile
tails, and Podoviridae have short tails. T4 phage is a classic example of Myoviridae.
🟢 5. A virus is found to contain a genome that is composed of eight separate RNA segments. This genomic organization is characteristic of which viral
family?
A. Paramyxoviridae
B. Coronaviridae
C. Orthomyxoviridae
D. Rhabdoviridae
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Orthomyxoviridae</span>
Rationale: Orthomyxoviridae (influenza viruses) have segmented RNA genomes consisting of eight separate RNA segments. Paramyxoviridae and
Rhabdoviridae have non-segmented genomes, and Coronaviridae have a single large positive-sense RNA genome.
🟢 6. Which of the following viruses possesses a genome that is partially double-stranded and partially single-stranded DNA?
A. Human papillomavirus
B. Hepatitis B virus
C. Herpes simplex virus
D. Adenovirus
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Hepatitis B virus</span>
Rationale: Hepatitis B virus (HBV) has a partially double-stranded circular DNA genome with a gap in the plus strand. This unique genome structure is
characteristic of the Hepadnaviridae family.
🟢 7. A researcher is analyzing the protein composition of a viral capsid and finds that it contains 180 copies of a single protein arranged in an icosahedral
symmetry with triangulation number T=3. This arrangement is typical of:
A. Small, simple viruses with limited genetic capacity
B. Complex viruses with multiple structural proteins
C. Enveloped viruses with matrix proteins
D. Bacteriophages with tail structures
<span style="color:red;border:1px solid red;padding:2px 6px;">A. Small, simple viruses with limited genetic capacity</span>
Rationale: Small, simple viruses often have capsids composed of multiple copies of a single protein arranged in icosahedral symmetry. The triangulation
number (T) describes the organization of the capsid. T=3 is common among small RNA viruses like poliovirus.
🟢 8. The presence of a tegument layer in a virus is associated with which viral family?
A. Picornaviridae
B. Herpesviridae
,C. Paramyxoviridae
D. Orthomyxoviridae
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Herpesviridae</span>
Rationale: The tegument is an amorphous protein layer found between the capsid and envelope of herpesviruses. It contains viral proteins that are
released into the host cell upon infection to modulate host cell processes.
🟢 9. Which of the following statements accurately compares the genomes of RNA viruses and DNA viruses?
A. RNA viruses generally have larger genomes than DNA viruses
B. DNA viruses generally have lower mutation rates than RNA viruses due to proofreading activity of DNA polymerases
C. RNA viruses are always single-stranded and DNA viruses are always double-stranded
D. DNA viruses replicate exclusively in the cytoplasm
<span style="color:red;border:1px solid red;padding:2px 6px;">B. DNA viruses generally have lower mutation rates than RNA viruses due
to proofreading activity of DNA polymerases</span>
Rationale: DNA polymerases have proofreading activity, resulting in lower mutation rates during DNA replication. RNA-dependent RNA polymerases lack
proofreading activity, leading to higher mutation rates in RNA viruses.
🟢 10. A virus is described as having a "complex" capsid morphology. Which of the following viruses BEST exemplifies this structural type?
A. Poliovirus
B. Tobacco mosaic virus
C. Bacteriophage T4
D. Influenza virus
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Bacteriophage T4</span>
Rationale: Complex capsid morphology includes structures that are neither purely icosahedral nor helical. Bacteriophage T4 has a complex structure with
an icosahedral head, a contractile tail, and tail fibers.
🟢 11. The matrix protein (M protein) of enveloped viruses functions to:
A. Form the viral envelope bilayer
B. Mediate attachment to host cell receptors
C. Bridge the viral envelope and capsid, and facilitate virion assembly and budding
D. Replicate the viral genome
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Bridge the viral envelope and capsid, and facilitate virion assembly and
budding</span>
Rationale: Matrix proteins (M proteins) are located between the capsid and envelope of enveloped viruses. They play a critical role in virion assembly,
budding, and maintaining the structure of the virion.
🟢 12. Which of the following viral genome types requires the virion to carry its own RNA-dependent RNA polymerase for the initiation of infection?
A. Positive-sense ssRNA genome
B. Double-stranded DNA genome
C. Negative-sense ssRNA genome
D. Double-stranded RNA genome
, <span style="color:red;border:1px solid red;padding:2px 6px;">C. Negative-sense ssRNA genome</span>
Rationale: Negative-sense ssRNA genomes cannot be directly translated by host ribosomes. The virion must carry its own RNA-dependent RNA
polymerase to transcribe the negative-sense genome into positive-sense mRNA.
🟢 13. A viral capsid protein is found to contain a nuclear localization signal (NLS). This suggests that the virus:
A. Replicates in the cytoplasm
B. Replicates in the nucleus
C. Buds from the plasma membrane
D. Is non-enveloped
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Replicates in the nucleus</span>
Rationale: Nuclear localization signals (NLS) direct proteins to the nucleus. Capsid proteins containing NLS indicate that the virus traffics to and replicates
in the nucleus (e.g., herpesviruses, adenoviruses).
🟢 14. The viral glycoprotein hemagglutinin (HA) is found on the surface of:
A. HIV
B. Herpes simplex virus
C. Influenza virus
D. Hepatitis B virus
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Influenza virus</span>
Rationale: Hemagglutinin (HA) and neuraminidase (NA) are surface glycoproteins found on influenza viruses. HA mediates attachment to sialic acid
receptors on host cells, and NA facilitates viral release.
🟢 15. A virus has a genome that is a circular, double-stranded DNA molecule of approximately 8,000 base pairs that replicates using a rolling circle
mechanism. This genome is characteristic of which virus?
A. Herpes simplex virus
B. Bacteriophage lambda
C. Hepatitis B virus
D. Human papillomavirus
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Bacteriophage lambda</span>
Rationale: Bacteriophage lambda has a circular, double-stranded DNA genome that replicates via a rolling circle mechanism during the lytic cycle.
Herpesviruses have large linear genomes, HBV has partially dsDNA, and HPV has circular dsDNA but replicates differently.
🟢 16. Which of the following is TRUE regarding the viral capsid in terms of antigenicity?
A. The capsid is not recognized by the immune system because it is hidden
B. The capsid is the primary target of neutralizing antibodies for non-enveloped viruses
C. Enveloped viruses do not have capsid proteins exposed to antibodies
D. Capsid proteins are not immunogenic
<span style="color:red;border:1px solid red;padding:2px 6px;">B. The capsid is the primary target of neutralizing antibodies for non-
enveloped viruses</span>
Pathogenesis Mechanisms, Antiviral Pharmacology, and Diagnostic Interpretation for Portage
Learning LockDown Browser Comprehensive Assessment
SECTION 1: VIRAL STRUCTURE, CLASSIFICATION, AND GENOME DIVERSITY (Questions 1-25)
🟢 1. A novel virus is isolated from a thermal vent archaeon. Structural analysis reveals a lipid monolayer surrounding the capsid rather than a bilayer. This
unique envelope structure is most likely derived from:
A. The host archaeal plasma membrane, which contains ether-linked lipids forming a monolayer
B. The nuclear membrane of the host cell
C. A unique viral-encoded lipid synthesis pathway
D. The endoplasmic reticulum of the host cell
<span style="color:red;border:1px solid red;padding:2px 6px;">A. The host archaeal plasma membrane, which contains ether-linked lipids
forming a monolayer</span>
Rationale: Archaeal membranes are composed of ether-linked lipids that form a monolayer rather than the phospholipid bilayer found in bacterial and
eukaryotic membranes. Viruses that infect archaea acquire envelopes from the host membrane.
🟢 2. A virologist determines that a newly discovered virus has a genome consisting of 12,000 nucleotides of positive-sense single-stranded RNA with a 5'
cap and 3' polyadenylated tail. Based on this information, which of the following statements is MOST accurate regarding the virus's replication strategy?
A. The viral genome must first be converted to double-stranded DNA by reverse transcriptase
B. The viral genome cannot be translated until it is replicated by viral RNA-dependent RNA polymerase
C. The viral genome can be directly translated by host ribosomes to produce viral polyproteins
D. The viral genome requires host DNA-dependent RNA polymerase for transcription
<span style="color:red;border:1px solid red;padding:2px 6px;">C. The viral genome can be directly translated by host ribosomes to
produce viral polyproteins</span>
Rationale: Positive-sense single-stranded RNA viruses have genomes that function as mRNA. The presence of a 5' cap and 3' poly(A) tail indicates that the
genome is ready for translation by host ribosomes.
🟢 3. Which of the following correctly describes the Baltimore classification group that includes viruses with a negative-sense single-stranded RNA
genome?
A. Group III: dsRNA viruses
B. Group IV: positive-sense ssRNA viruses
C. Group V: negative-sense ssRNA viruses
D. Group VI: ssRNA-RT viruses
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Group V: negative-sense ssRNA viruses</span>
Rationale: The Baltimore classification groups viruses based on their genome type and replication strategy. Group V includes viruses with negative-sense
single-stranded RNA genomes (e.g., Ebola, influenza, rabies).
🟢 4. A bacteriophage is observed to have an icosahedral head, a contractile tail sheath, and tail fibers. This phage is BEST classified as a member of the:
,A. Myoviridae family (contractile tails)
B. Siphoviridae family (long non-contractile tails)
C. Podoviridae family (short tails)
D. Inoviridae family (filamentous)
<span style="color:red;border:1px solid red;padding:2px 6px;">A. Myoviridae family (contractile tails)</span>
Rationale: Bacteriophages are classified into families based on tail morphology. Myoviridae have contractile tails, Siphoviridae have long non-contractile
tails, and Podoviridae have short tails. T4 phage is a classic example of Myoviridae.
🟢 5. A virus is found to contain a genome that is composed of eight separate RNA segments. This genomic organization is characteristic of which viral
family?
A. Paramyxoviridae
B. Coronaviridae
C. Orthomyxoviridae
D. Rhabdoviridae
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Orthomyxoviridae</span>
Rationale: Orthomyxoviridae (influenza viruses) have segmented RNA genomes consisting of eight separate RNA segments. Paramyxoviridae and
Rhabdoviridae have non-segmented genomes, and Coronaviridae have a single large positive-sense RNA genome.
🟢 6. Which of the following viruses possesses a genome that is partially double-stranded and partially single-stranded DNA?
A. Human papillomavirus
B. Hepatitis B virus
C. Herpes simplex virus
D. Adenovirus
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Hepatitis B virus</span>
Rationale: Hepatitis B virus (HBV) has a partially double-stranded circular DNA genome with a gap in the plus strand. This unique genome structure is
characteristic of the Hepadnaviridae family.
🟢 7. A researcher is analyzing the protein composition of a viral capsid and finds that it contains 180 copies of a single protein arranged in an icosahedral
symmetry with triangulation number T=3. This arrangement is typical of:
A. Small, simple viruses with limited genetic capacity
B. Complex viruses with multiple structural proteins
C. Enveloped viruses with matrix proteins
D. Bacteriophages with tail structures
<span style="color:red;border:1px solid red;padding:2px 6px;">A. Small, simple viruses with limited genetic capacity</span>
Rationale: Small, simple viruses often have capsids composed of multiple copies of a single protein arranged in icosahedral symmetry. The triangulation
number (T) describes the organization of the capsid. T=3 is common among small RNA viruses like poliovirus.
🟢 8. The presence of a tegument layer in a virus is associated with which viral family?
A. Picornaviridae
B. Herpesviridae
,C. Paramyxoviridae
D. Orthomyxoviridae
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Herpesviridae</span>
Rationale: The tegument is an amorphous protein layer found between the capsid and envelope of herpesviruses. It contains viral proteins that are
released into the host cell upon infection to modulate host cell processes.
🟢 9. Which of the following statements accurately compares the genomes of RNA viruses and DNA viruses?
A. RNA viruses generally have larger genomes than DNA viruses
B. DNA viruses generally have lower mutation rates than RNA viruses due to proofreading activity of DNA polymerases
C. RNA viruses are always single-stranded and DNA viruses are always double-stranded
D. DNA viruses replicate exclusively in the cytoplasm
<span style="color:red;border:1px solid red;padding:2px 6px;">B. DNA viruses generally have lower mutation rates than RNA viruses due
to proofreading activity of DNA polymerases</span>
Rationale: DNA polymerases have proofreading activity, resulting in lower mutation rates during DNA replication. RNA-dependent RNA polymerases lack
proofreading activity, leading to higher mutation rates in RNA viruses.
🟢 10. A virus is described as having a "complex" capsid morphology. Which of the following viruses BEST exemplifies this structural type?
A. Poliovirus
B. Tobacco mosaic virus
C. Bacteriophage T4
D. Influenza virus
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Bacteriophage T4</span>
Rationale: Complex capsid morphology includes structures that are neither purely icosahedral nor helical. Bacteriophage T4 has a complex structure with
an icosahedral head, a contractile tail, and tail fibers.
🟢 11. The matrix protein (M protein) of enveloped viruses functions to:
A. Form the viral envelope bilayer
B. Mediate attachment to host cell receptors
C. Bridge the viral envelope and capsid, and facilitate virion assembly and budding
D. Replicate the viral genome
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Bridge the viral envelope and capsid, and facilitate virion assembly and
budding</span>
Rationale: Matrix proteins (M proteins) are located between the capsid and envelope of enveloped viruses. They play a critical role in virion assembly,
budding, and maintaining the structure of the virion.
🟢 12. Which of the following viral genome types requires the virion to carry its own RNA-dependent RNA polymerase for the initiation of infection?
A. Positive-sense ssRNA genome
B. Double-stranded DNA genome
C. Negative-sense ssRNA genome
D. Double-stranded RNA genome
, <span style="color:red;border:1px solid red;padding:2px 6px;">C. Negative-sense ssRNA genome</span>
Rationale: Negative-sense ssRNA genomes cannot be directly translated by host ribosomes. The virion must carry its own RNA-dependent RNA
polymerase to transcribe the negative-sense genome into positive-sense mRNA.
🟢 13. A viral capsid protein is found to contain a nuclear localization signal (NLS). This suggests that the virus:
A. Replicates in the cytoplasm
B. Replicates in the nucleus
C. Buds from the plasma membrane
D. Is non-enveloped
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Replicates in the nucleus</span>
Rationale: Nuclear localization signals (NLS) direct proteins to the nucleus. Capsid proteins containing NLS indicate that the virus traffics to and replicates
in the nucleus (e.g., herpesviruses, adenoviruses).
🟢 14. The viral glycoprotein hemagglutinin (HA) is found on the surface of:
A. HIV
B. Herpes simplex virus
C. Influenza virus
D. Hepatitis B virus
<span style="color:red;border:1px solid red;padding:2px 6px;">C. Influenza virus</span>
Rationale: Hemagglutinin (HA) and neuraminidase (NA) are surface glycoproteins found on influenza viruses. HA mediates attachment to sialic acid
receptors on host cells, and NA facilitates viral release.
🟢 15. A virus has a genome that is a circular, double-stranded DNA molecule of approximately 8,000 base pairs that replicates using a rolling circle
mechanism. This genome is characteristic of which virus?
A. Herpes simplex virus
B. Bacteriophage lambda
C. Hepatitis B virus
D. Human papillomavirus
<span style="color:red;border:1px solid red;padding:2px 6px;">B. Bacteriophage lambda</span>
Rationale: Bacteriophage lambda has a circular, double-stranded DNA genome that replicates via a rolling circle mechanism during the lytic cycle.
Herpesviruses have large linear genomes, HBV has partially dsDNA, and HPV has circular dsDNA but replicates differently.
🟢 16. Which of the following is TRUE regarding the viral capsid in terms of antigenicity?
A. The capsid is not recognized by the immune system because it is hidden
B. The capsid is the primary target of neutralizing antibodies for non-enveloped viruses
C. Enveloped viruses do not have capsid proteins exposed to antibodies
D. Capsid proteins are not immunogenic
<span style="color:red;border:1px solid red;padding:2px 6px;">B. The capsid is the primary target of neutralizing antibodies for non-
enveloped viruses</span>
