, BIOD 171 Essential Microbiology Module 6 Exam – Actual
Questions with Verified Answers (2026/2027 Updated) –
Portage Learning EXAM with Questions and Answers/Plus a
Rationale Updated 2026 A+/Instant Download PDF
EXAM COVERAGE
1. Viral Structure and Basic Components
2. Viral Classification and Nomenclature
3. Viral Replication Cycles (Lytic vs. Lysogenic/Temperate)
4. Bacteriophages and Structural Morphology
5. Enveloped vs. Non-Enveloped Viruses
6. Respiratory and Exanthematous Viral Pathogens (Measles, Mumps, Rubella)
7. Poxviruses and Orthomyxoviruses (Smallpox, Influenza)
8. Herpesviruses and Varicella- Zoster Virus (Chickenpox and Shingles)
9. Picornaviruses and Poliovirus Pathogenesis
10. Retroviruses and Human Immunodeficiency Virus (HIV) Mechanisms
1. Which of the following best describes the fundamental classification status of viruses regarding
cellular organization?
A. Prokaryotic unicellular microorganisms
B. Eukaryotic acellular infectious agents
, C. Neither prokaryotic nor eukaryotic acellular entities
D. Primitive parasitic bacteria lacking cell walls
CORRECT ANSWER : C
Rationale: Viruses are completely acellular and do not possess cellular machinery, organelles,
or metabolic pathways, meaning they are classified neither as prokaryotes nor as eukaryotes.
They exist strictly as obligate intracellular entities relying entirely on host cellular systems for
replication.
2. What are the two essential components that comprise all basic viral particles (virions)?
A. A lipid bilayer and ribosomal RNA
B. A proteinaceous cell wall and genomic DNA
C. Genomic material enclosed within a protein capsid
D. An outer envelope and intracellular mitochondria
CORRECT ANSWER : C
Rationale: All basic virions consist of a central genome composed of either DNA or RNA and a
protective protein coat called a capsid. Together, these form the core structural unit required for
protection and host cell interaction.
3. How does the presence of a viral envelope typically correlate with the specific host cell type
being infected?
A. Plant-infecting viruses universally possess complex outer envelopes.
B. The overwhelming majority of animal viruses are enveloped, whereas plant or bacterial
viruses are not.
C. Bacterial phages always acquire a host-derived lipid envelope upon exit.
D. Enveloped viruses are exclusively restricted to fungal hosts.
CORRECT ANSWER : B
Rationale: Viral envelopes are lipid bilayer structures derived from host cell membranes during
budding. Consequently, most animal viruses are enveloped to aid in immune evasion and cell
fusion, whereas plant and bacterial viruses typically lack envelopes due to rigid cell walls.
, 4. Which of the following correctly ranks representative viruses from largest to smallest based on
typical virion size?
A. Poliovirus > Orthomyxovirus > Variolavirus
B. Orthomyxovirus > Variolavirus > Poliovirus
C. Variolavirus > Orthomyxovirus > Poliovirus
D. Poliovirus > Variolavirus > Orthomyxovirus
CORRECT ANSWER : C
Rationale: Variolavirus (Smallpox) is among the largest and most complex DNA viruses (~200
nm), Orthomyxoviruses (Influenza) have moderate-sized enveloped RNA structures (100-150
nm), and Poliovirus is a very small non-enveloped RNA virus (~30 nm).
5. True or False: Highly infectious viruses typically undergo full genomic replication prior to viral
attachment and entry into the host cell.
A. True
B. False
C. Only in bacterial phages
D. Only in retroviruses
CORRECT ANSWER : B
Rationale: Viral replication of the genome is strictly dependent on successful attachment, entry,
and uncoating within a living host cell. Viruses cannot replicate their genomes extracellularly.
6. What specific structural characteristic defines the capsid symmetry of a typical bacteriophage?
A. Helical hollow cylinders with flexible tails
B. An icosahedral head featuring twenty equilateral triangular faces
C. Complex spherical pleomorphic envelopes
D. Filamentous unbranched spiral chains
CORRECT ANSWER : B
Questions with Verified Answers (2026/2027 Updated) –
Portage Learning EXAM with Questions and Answers/Plus a
Rationale Updated 2026 A+/Instant Download PDF
EXAM COVERAGE
1. Viral Structure and Basic Components
2. Viral Classification and Nomenclature
3. Viral Replication Cycles (Lytic vs. Lysogenic/Temperate)
4. Bacteriophages and Structural Morphology
5. Enveloped vs. Non-Enveloped Viruses
6. Respiratory and Exanthematous Viral Pathogens (Measles, Mumps, Rubella)
7. Poxviruses and Orthomyxoviruses (Smallpox, Influenza)
8. Herpesviruses and Varicella- Zoster Virus (Chickenpox and Shingles)
9. Picornaviruses and Poliovirus Pathogenesis
10. Retroviruses and Human Immunodeficiency Virus (HIV) Mechanisms
1. Which of the following best describes the fundamental classification status of viruses regarding
cellular organization?
A. Prokaryotic unicellular microorganisms
B. Eukaryotic acellular infectious agents
, C. Neither prokaryotic nor eukaryotic acellular entities
D. Primitive parasitic bacteria lacking cell walls
CORRECT ANSWER : C
Rationale: Viruses are completely acellular and do not possess cellular machinery, organelles,
or metabolic pathways, meaning they are classified neither as prokaryotes nor as eukaryotes.
They exist strictly as obligate intracellular entities relying entirely on host cellular systems for
replication.
2. What are the two essential components that comprise all basic viral particles (virions)?
A. A lipid bilayer and ribosomal RNA
B. A proteinaceous cell wall and genomic DNA
C. Genomic material enclosed within a protein capsid
D. An outer envelope and intracellular mitochondria
CORRECT ANSWER : C
Rationale: All basic virions consist of a central genome composed of either DNA or RNA and a
protective protein coat called a capsid. Together, these form the core structural unit required for
protection and host cell interaction.
3. How does the presence of a viral envelope typically correlate with the specific host cell type
being infected?
A. Plant-infecting viruses universally possess complex outer envelopes.
B. The overwhelming majority of animal viruses are enveloped, whereas plant or bacterial
viruses are not.
C. Bacterial phages always acquire a host-derived lipid envelope upon exit.
D. Enveloped viruses are exclusively restricted to fungal hosts.
CORRECT ANSWER : B
Rationale: Viral envelopes are lipid bilayer structures derived from host cell membranes during
budding. Consequently, most animal viruses are enveloped to aid in immune evasion and cell
fusion, whereas plant and bacterial viruses typically lack envelopes due to rigid cell walls.
, 4. Which of the following correctly ranks representative viruses from largest to smallest based on
typical virion size?
A. Poliovirus > Orthomyxovirus > Variolavirus
B. Orthomyxovirus > Variolavirus > Poliovirus
C. Variolavirus > Orthomyxovirus > Poliovirus
D. Poliovirus > Variolavirus > Orthomyxovirus
CORRECT ANSWER : C
Rationale: Variolavirus (Smallpox) is among the largest and most complex DNA viruses (~200
nm), Orthomyxoviruses (Influenza) have moderate-sized enveloped RNA structures (100-150
nm), and Poliovirus is a very small non-enveloped RNA virus (~30 nm).
5. True or False: Highly infectious viruses typically undergo full genomic replication prior to viral
attachment and entry into the host cell.
A. True
B. False
C. Only in bacterial phages
D. Only in retroviruses
CORRECT ANSWER : B
Rationale: Viral replication of the genome is strictly dependent on successful attachment, entry,
and uncoating within a living host cell. Viruses cannot replicate their genomes extracellularly.
6. What specific structural characteristic defines the capsid symmetry of a typical bacteriophage?
A. Helical hollow cylinders with flexible tails
B. An icosahedral head featuring twenty equilateral triangular faces
C. Complex spherical pleomorphic envelopes
D. Filamentous unbranched spiral chains
CORRECT ANSWER : B
