BIOL271: Microbiology w/Lab
2026 – 2027 | Portage Learning
Module 6: Virus Characterization, Morphology and Pathogenic Causative Agents
Exam Review | LockDown Browser
By PortageMaster
Question 1
Because the genome is contained within an enclosed space (much like the nucleus of a cell),
viruses are classified as eukaryotic. True or False?
• True
• ✓ False
Correct Answer: False
Feedback: Viruses are neither eukaryotic nor prokaryotic — they are acellular and lack the cellular
machinery of either domain.
Question 2
Although viruses may contain their genome within an enclosed space (much like the nucleus of a
cell), it is considered neither eukaryotic nor prokaryotic. True or False?
• ✓ True
• False
Correct Answer: True
Feedback: Viruses fall outside the standard cellular classification scheme — they are obligate
intracellular parasites.
Question 3
Describe the two basic components of a virus.
✓ Answer: (1) Genomic material made up of either DNA or RNA, and (2) a capsid — a
protein structure that protects and contains the genetic material.
Feedback: Some viruses additionally have an envelope of host-derived lipid membrane surrounding
the capsid.
, Question 4
You would expect to see a viral envelope on a virus infecting a bacterial cell. True or False?
• True
• ✓ False
Correct Answer: False
Feedback: The overwhelming majority of animal viruses are enveloped, whereas most plant- and
bacteria-infecting viruses are not.
Question 5
The envelope surrounds the ______ of some viruses.
✓ Answer: Capsid
Feedback: When present, the lipid envelope wraps around the protein capsid.
Question 6
The ______ surrounds the capsid of some viruses.
✓ Answer: Envelope
Feedback: Envelopes are derived from the host cell membrane and studded with viral glycoproteins.
Question 7
Rank the following viruses by size, largest to smallest: Paramyxovirus, Poliovirus, Smallpox virus.
✓ Answer: Smallpox > Paramyxovirus > Poliovirus
Feedback: Smallpox (~300 nm) > Paramyxovirus (~150–300 nm) > Poliovirus (~30 nm).
Question 8
Rank the following viruses by size, largest to smallest: Orthomyxovirus, Poliovirus, Variolavirus.
✓ Answer: Variolavirus > Orthomyxovirus > Poliovirus
Feedback: Variolavirus (smallpox, ~300 nm) > Orthomyxovirus (influenza, ~100 nm) > Poliovirus (~30
nm).
Question 9
Highly infectious viruses undergo genome replication prior to viral attachment and entry. True or
False?
• True
• ✓ False
Correct Answer: False
Feedback: Replication occurs after attachment and entry into a host cell — viruses cannot replicate
outside of a host.
2026 – 2027 | Portage Learning
Module 6: Virus Characterization, Morphology and Pathogenic Causative Agents
Exam Review | LockDown Browser
By PortageMaster
Question 1
Because the genome is contained within an enclosed space (much like the nucleus of a cell),
viruses are classified as eukaryotic. True or False?
• True
• ✓ False
Correct Answer: False
Feedback: Viruses are neither eukaryotic nor prokaryotic — they are acellular and lack the cellular
machinery of either domain.
Question 2
Although viruses may contain their genome within an enclosed space (much like the nucleus of a
cell), it is considered neither eukaryotic nor prokaryotic. True or False?
• ✓ True
• False
Correct Answer: True
Feedback: Viruses fall outside the standard cellular classification scheme — they are obligate
intracellular parasites.
Question 3
Describe the two basic components of a virus.
✓ Answer: (1) Genomic material made up of either DNA or RNA, and (2) a capsid — a
protein structure that protects and contains the genetic material.
Feedback: Some viruses additionally have an envelope of host-derived lipid membrane surrounding
the capsid.
, Question 4
You would expect to see a viral envelope on a virus infecting a bacterial cell. True or False?
• True
• ✓ False
Correct Answer: False
Feedback: The overwhelming majority of animal viruses are enveloped, whereas most plant- and
bacteria-infecting viruses are not.
Question 5
The envelope surrounds the ______ of some viruses.
✓ Answer: Capsid
Feedback: When present, the lipid envelope wraps around the protein capsid.
Question 6
The ______ surrounds the capsid of some viruses.
✓ Answer: Envelope
Feedback: Envelopes are derived from the host cell membrane and studded with viral glycoproteins.
Question 7
Rank the following viruses by size, largest to smallest: Paramyxovirus, Poliovirus, Smallpox virus.
✓ Answer: Smallpox > Paramyxovirus > Poliovirus
Feedback: Smallpox (~300 nm) > Paramyxovirus (~150–300 nm) > Poliovirus (~30 nm).
Question 8
Rank the following viruses by size, largest to smallest: Orthomyxovirus, Poliovirus, Variolavirus.
✓ Answer: Variolavirus > Orthomyxovirus > Poliovirus
Feedback: Variolavirus (smallpox, ~300 nm) > Orthomyxovirus (influenza, ~100 nm) > Poliovirus (~30
nm).
Question 9
Highly infectious viruses undergo genome replication prior to viral attachment and entry. True or
False?
• True
• ✓ False
Correct Answer: False
Feedback: Replication occurs after attachment and entry into a host cell — viruses cannot replicate
outside of a host.
