PORTAGE LEARNING
Bachelor of Science in Nursing (BSN)
BIOL 271 / BIOL 271 Module 6 — Microbiology
Academic Year: 2026/2027 Module 6 · Virology Question Bank NCLEX-style
Q1 What is a provirus?
A. Viral DNA that has integrated into the genomic DNA of a eukaryotic host cell
B. Bacteriophage DNA that has integrated into the host bacterial genome
C. A newly formed viral particle
D. The protein coat of a virus
CORRECT ANSWER:
A. Viral DNA that has integrated into the genomic DNA of a eukaryotic host
cell
— RATIONALE
A provirus is integrated viral DNA in a eukaryotic host genome. Unlike a prophage
(bacterial), the provirus remains integrated and can be transcribed to produce new
viruses. This is characteristic of retroviruses like HIV.
,Q2 What are the characteristics of Influenza A?
A. Infects humans and animals; causes severe disease, annual epidemics, and
occasional global pandemics
B. Infects primarily humans; causes seasonal epidemics but does not cause global
pandemics
C. Infects humans and pigs; causes mild respiratory illness and does not cause
epidemics
D. Infects only birds
CORRECT ANSWER:
A. Infects humans and animals; causes severe disease, annual epidemics, and
occasional global pandemics
— RATIONALE
Influenza A viruses have a broad host range (humans, birds, pigs). They are responsible
for seasonal epidemics and pandemics due to their ability to undergo antigenic shift and
drift.
Q3 What is a live-attenuated vaccine?
A. A vaccine containing weakened, active wild virus that stimulates a strong immune
response
B. A vaccine containing inactivated (killed) virus
C. A vaccine containing only viral proteins
D. A vaccine that contains no viral components
CORRECT ANSWER:
A. A vaccine containing weakened, active wild virus that stimulates a strong
immune response
— RATIONALE
Live-attenuated vaccines use weakened (attenuated) forms of the pathogen that can still
replicate but do not cause disease. They elicit strong humoral and cellular immune
responses (e.g., MMR, varicella).
,Q4 What is the primary natural reservoir for Influenza A?
A. Wild aquatic birds (waterfowl)
B. Domestic pigs
C. Humans
D. Horses
CORRECT ANSWER: A. Wild aquatic birds (waterfowl)
— RATIONALE
The primary natural reservoir for Influenza A is wild aquatic birds (ducks, geese,
shorebirds). These birds harbor all known HA and NA subtypes and serve as the source
for novel strains.
Q5 What is active immunity?
A. Immunity acquired through receiving pre-formed antibodies from another source
B. Immunity produced by the body's own immune response to an antigen exposure
C. Immunity that does not require immune memory
D. Immunity that is present at birth
CORRECT ANSWER:
B. Immunity produced by the body's own immune response to an antigen
exposure
— RATIONALE
Active immunity develops when the body's immune system produces antibodies and
memory cells in response to natural infection or vaccination. It is long-lasting and
provides immunological memory.
, Q6 What is the morphology of poliovirus?
A. Enveloped, ~200 nm long, dumbbell-shaped capsid
B. Non-enveloped, ~30 nm in diameter
C. Enveloped, ~100 nm diameter, spherical
D. Non-enveloped, ~100 nm diameter, icosahedral
CORRECT ANSWER: B. Non-enveloped, ~30 nm in diameter
— RATIONALE
Poliovirus is a small, non-enveloped virus belonging to the Picornaviridae family. It has an
icosahedral capsid and measures approximately 30 nm in diameter, making it one of the
smallest known viruses.
Q7 What are the generalized steps of the viral life cycle?
A. Attachment, entry, uncoating, transcription/translation, genome replication,
assembly, and release
B. Attachment, replication, assembly, release
C. Entry, uncoating, replication, release
D. Attachment, entry, assembly, release
CORRECT ANSWER:
A. Attachment, entry, uncoating, transcription/translation, genome replication,
assembly, and release
— RATIONALE
The viral life cycle follows a general sequence: attachment to host receptors, entry into
the cell, uncoating of the viral genome, transcription/translation of viral proteins, genome
replication, assembly of new virions, and release from the host cell.
Bachelor of Science in Nursing (BSN)
BIOL 271 / BIOL 271 Module 6 — Microbiology
Academic Year: 2026/2027 Module 6 · Virology Question Bank NCLEX-style
Q1 What is a provirus?
A. Viral DNA that has integrated into the genomic DNA of a eukaryotic host cell
B. Bacteriophage DNA that has integrated into the host bacterial genome
C. A newly formed viral particle
D. The protein coat of a virus
CORRECT ANSWER:
A. Viral DNA that has integrated into the genomic DNA of a eukaryotic host
cell
— RATIONALE
A provirus is integrated viral DNA in a eukaryotic host genome. Unlike a prophage
(bacterial), the provirus remains integrated and can be transcribed to produce new
viruses. This is characteristic of retroviruses like HIV.
,Q2 What are the characteristics of Influenza A?
A. Infects humans and animals; causes severe disease, annual epidemics, and
occasional global pandemics
B. Infects primarily humans; causes seasonal epidemics but does not cause global
pandemics
C. Infects humans and pigs; causes mild respiratory illness and does not cause
epidemics
D. Infects only birds
CORRECT ANSWER:
A. Infects humans and animals; causes severe disease, annual epidemics, and
occasional global pandemics
— RATIONALE
Influenza A viruses have a broad host range (humans, birds, pigs). They are responsible
for seasonal epidemics and pandemics due to their ability to undergo antigenic shift and
drift.
Q3 What is a live-attenuated vaccine?
A. A vaccine containing weakened, active wild virus that stimulates a strong immune
response
B. A vaccine containing inactivated (killed) virus
C. A vaccine containing only viral proteins
D. A vaccine that contains no viral components
CORRECT ANSWER:
A. A vaccine containing weakened, active wild virus that stimulates a strong
immune response
— RATIONALE
Live-attenuated vaccines use weakened (attenuated) forms of the pathogen that can still
replicate but do not cause disease. They elicit strong humoral and cellular immune
responses (e.g., MMR, varicella).
,Q4 What is the primary natural reservoir for Influenza A?
A. Wild aquatic birds (waterfowl)
B. Domestic pigs
C. Humans
D. Horses
CORRECT ANSWER: A. Wild aquatic birds (waterfowl)
— RATIONALE
The primary natural reservoir for Influenza A is wild aquatic birds (ducks, geese,
shorebirds). These birds harbor all known HA and NA subtypes and serve as the source
for novel strains.
Q5 What is active immunity?
A. Immunity acquired through receiving pre-formed antibodies from another source
B. Immunity produced by the body's own immune response to an antigen exposure
C. Immunity that does not require immune memory
D. Immunity that is present at birth
CORRECT ANSWER:
B. Immunity produced by the body's own immune response to an antigen
exposure
— RATIONALE
Active immunity develops when the body's immune system produces antibodies and
memory cells in response to natural infection or vaccination. It is long-lasting and
provides immunological memory.
, Q6 What is the morphology of poliovirus?
A. Enveloped, ~200 nm long, dumbbell-shaped capsid
B. Non-enveloped, ~30 nm in diameter
C. Enveloped, ~100 nm diameter, spherical
D. Non-enveloped, ~100 nm diameter, icosahedral
CORRECT ANSWER: B. Non-enveloped, ~30 nm in diameter
— RATIONALE
Poliovirus is a small, non-enveloped virus belonging to the Picornaviridae family. It has an
icosahedral capsid and measures approximately 30 nm in diameter, making it one of the
smallest known viruses.
Q7 What are the generalized steps of the viral life cycle?
A. Attachment, entry, uncoating, transcription/translation, genome replication,
assembly, and release
B. Attachment, replication, assembly, release
C. Entry, uncoating, replication, release
D. Attachment, entry, assembly, release
CORRECT ANSWER:
A. Attachment, entry, uncoating, transcription/translation, genome replication,
assembly, and release
— RATIONALE
The viral life cycle follows a general sequence: attachment to host receptors, entry into
the cell, uncoating of the viral genome, transcription/translation of viral proteins, genome
replication, assembly of new virions, and release from the host cell.
