BIOD 171 Microbiology Module 6 Exam – Portage
learning 2026 Actual Exam
T/F: Because the genome is contained within an enclosed space (much like the nucleus of a
cell) viruses are classified as eukaryotic
False. Viruses are neither eukaryotic nor prokaryotic
Describe the two basic components of a virus.
A virus has (1) genomic material comprised of either DNA or RNA and (2) a capsid, a membrane-
like protective structure that contains the genetic material, similar to the nucleus of a eukaryotic
cell.
The ____ surrounds the capsid of some viruses
Envelope
True or False: You would expect to see a viral envelope on a virus infecting a plant cell
False. The overwhelming majority of animal viruses are enveloped whereas the majority of
plant or bacteria-infecting viruses are not
Rank the following viruses based on their size from largest to smallest:
1. Variolavirus, orthomyxovirus, polivirus
True or false: viral replication occurs after it attaches and enters the host cell
True. the viral genome is never replicated before attachment and entry
Place the following viral life cycle steps in order beginning with viral attachment and provide a
description of each step
3- Uncoating: the viral capsid disassembles
5-Release: New virus particles are produced and leave the cell
4-Replication: the viral genome is the 'blueprint' to make copies of itself
1-Attachment: viral receptors bind to host proteins on the surface of the cell
2-Entry: the virus fuses with the host membrane and enters the cell
6-New infection: newly produced viruses that left the host cell now go on to infect new cells
A virus that infects bacteria is called a _____ and contains a _____-side polygon capsid
, Bacteriophage; 20-sided
True or False: structurally, bacteriophages are similar to viruses that infect animals
False. Bacteriophages have a distinct composition and structure
1. Capsid (or head)
2. collar
3. tail (sheath)
4. base plate
5. tail fibers
Describe the main differences between lytic and temperate phages.
Lytic bacteriophages replicate within the host bacteria until it ruptures, whereas temporate
(or lysogenic) phages primarily exist in a non-replicative state that does not kill the host cell.
Lytic phages replicate all viral proteins needed for the assembly of new virus particles
whereas lysogenic phage genomes are integrated into the host genome but production of
viral proteins is suppressed.
Based on the following image, would you expect the viral titer to be high or low?
Low. As turbidity is a function of the number of intact bacterial cells present in the media, the
amount of virus contained must be low. As the lytic cycle continues more and more bacterial
cells will be destroyed, effectively clearing the media.
Which of the following can be spread via airborne particles:
A. Measles
B. Mumps
C. Rubella
D. A and B
E. All of the above
E. Measles, mumps and rubella can all be spread via airborne particles formed while
coughing, sneezing, etc.
True or False: a patient infected with Rubella is considered infectious one week before and
after the appearance of the trademark rash
True
True or false: a patient with rubella is only considered infectious when the trademark rash is
visible
learning 2026 Actual Exam
T/F: Because the genome is contained within an enclosed space (much like the nucleus of a
cell) viruses are classified as eukaryotic
False. Viruses are neither eukaryotic nor prokaryotic
Describe the two basic components of a virus.
A virus has (1) genomic material comprised of either DNA or RNA and (2) a capsid, a membrane-
like protective structure that contains the genetic material, similar to the nucleus of a eukaryotic
cell.
The ____ surrounds the capsid of some viruses
Envelope
True or False: You would expect to see a viral envelope on a virus infecting a plant cell
False. The overwhelming majority of animal viruses are enveloped whereas the majority of
plant or bacteria-infecting viruses are not
Rank the following viruses based on their size from largest to smallest:
1. Variolavirus, orthomyxovirus, polivirus
True or false: viral replication occurs after it attaches and enters the host cell
True. the viral genome is never replicated before attachment and entry
Place the following viral life cycle steps in order beginning with viral attachment and provide a
description of each step
3- Uncoating: the viral capsid disassembles
5-Release: New virus particles are produced and leave the cell
4-Replication: the viral genome is the 'blueprint' to make copies of itself
1-Attachment: viral receptors bind to host proteins on the surface of the cell
2-Entry: the virus fuses with the host membrane and enters the cell
6-New infection: newly produced viruses that left the host cell now go on to infect new cells
A virus that infects bacteria is called a _____ and contains a _____-side polygon capsid
, Bacteriophage; 20-sided
True or False: structurally, bacteriophages are similar to viruses that infect animals
False. Bacteriophages have a distinct composition and structure
1. Capsid (or head)
2. collar
3. tail (sheath)
4. base plate
5. tail fibers
Describe the main differences between lytic and temperate phages.
Lytic bacteriophages replicate within the host bacteria until it ruptures, whereas temporate
(or lysogenic) phages primarily exist in a non-replicative state that does not kill the host cell.
Lytic phages replicate all viral proteins needed for the assembly of new virus particles
whereas lysogenic phage genomes are integrated into the host genome but production of
viral proteins is suppressed.
Based on the following image, would you expect the viral titer to be high or low?
Low. As turbidity is a function of the number of intact bacterial cells present in the media, the
amount of virus contained must be low. As the lytic cycle continues more and more bacterial
cells will be destroyed, effectively clearing the media.
Which of the following can be spread via airborne particles:
A. Measles
B. Mumps
C. Rubella
D. A and B
E. All of the above
E. Measles, mumps and rubella can all be spread via airborne particles formed while
coughing, sneezing, etc.
True or False: a patient infected with Rubella is considered infectious one week before and
after the appearance of the trademark rash
True
True or false: a patient with rubella is only considered infectious when the trademark rash is
visible
