Portage Learning BIOD 171 Module 6
UPDATED ACTUAL Exam Questions and
CORRECT Answers
What is a viral capsid? - CORRECT ANSWER - The capsid is a membrane-like protective
structure that contains the genetic material, similar to the nucleus of a eukaryotic cell.
Can viruses be classified as either prokaryotic or eukaryotic? - CORRECT ANSWER -
No. Viruses are neither prokaryotic nor eukaryotic.
What is the viral envelope, and what does the presence (or absence) of it tell you about the type
of virus? - CORRECT ANSWER - The viral envelope surrounds the viral capsid and
serves as an additional barrier to the external environment. The majority of animal viruses are
enveloped where as plant or bacteria infecting viruses are not.
What type of microscope would be used to study the shape of a viral capsid? - CORRECT
ANSWER - Due to its size (~30-150 nm) most viral capsids must be visualized via
electron microscopy.
How does the viral envelope both aid in cell entry as well as hide it from being detected by the
immune system? - CORRECT ANSWER - It contains the proteins required for interaction
with host cells. As the envelope is derived from the host cell, this camouflages the virus and
makes it appear similar to the normal host cell.
What must happen before viral replication of its genome can occur? - CORRECT
ANSWER - The genome is replicated following attachment and entry
What is an obligate intracellular parasite? - CORRECT ANSWER - Viruses cannot
replicate unless inside a living host cell. A virus depends on its living host to provide the
framework to replicate.
, Describe the basic steps of the viral life cycle. - CORRECT ANSWER - 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
3. Uncoating: (where applicable) the viral capsid disassembles
4. Replication: The viral genome provides the 'blueprint' to make copies of itself
5. Exit: New viruses are produced and leave the cell
6. New infection: Newly produced viruses leave the host cell and go on to infect new cells. The
process outlined above now restarts.
What is a bacteriophage? - CORRECT ANSWER - A virus that infects bacteria
What structural aspects make bacteriophages distinct from viruses that infect either animals or
plants? - CORRECT ANSWER - They have an icosahedral capsid head and a helical tail.
Which viral replicative process results in the destruction of the host cell? - CORRECT
ANSWER - The lytic replication cycle
Describe the appearance of a bacterial culture infected with virus at the time of infection versus
later once viral replication is occurring at a high rate. - CORRECT ANSWER - It turns
from a turbid to clear, the bacterial cell numbers decrease due to lysis and the media becomes
clearer.
To what family of viruses does rubella come from and how is it transmitted? - CORRECT
ANSWER - Rubella comes from Togaviridae and it is transmitted by air-borne particles.
What is the common name for rubeola, and is it a DNA or RNA virus? - CORRECT
ANSWER - It is commonly known as measles and belongs to viruses called
Paramyxovirus. It is a RNA.
What disease state emerges as a viral reactivation of a prior infection with the varicella virus? -
CORRECT ANSWER - Shingles, also known as Herpes zoster, is due to the reactivation
of the varicella-zoster virus (VZV). Because VZV lies dormant in inactive nerve cells, its
UPDATED ACTUAL Exam Questions and
CORRECT Answers
What is a viral capsid? - CORRECT ANSWER - The capsid is a membrane-like protective
structure that contains the genetic material, similar to the nucleus of a eukaryotic cell.
Can viruses be classified as either prokaryotic or eukaryotic? - CORRECT ANSWER -
No. Viruses are neither prokaryotic nor eukaryotic.
What is the viral envelope, and what does the presence (or absence) of it tell you about the type
of virus? - CORRECT ANSWER - The viral envelope surrounds the viral capsid and
serves as an additional barrier to the external environment. The majority of animal viruses are
enveloped where as plant or bacteria infecting viruses are not.
What type of microscope would be used to study the shape of a viral capsid? - CORRECT
ANSWER - Due to its size (~30-150 nm) most viral capsids must be visualized via
electron microscopy.
How does the viral envelope both aid in cell entry as well as hide it from being detected by the
immune system? - CORRECT ANSWER - It contains the proteins required for interaction
with host cells. As the envelope is derived from the host cell, this camouflages the virus and
makes it appear similar to the normal host cell.
What must happen before viral replication of its genome can occur? - CORRECT
ANSWER - The genome is replicated following attachment and entry
What is an obligate intracellular parasite? - CORRECT ANSWER - Viruses cannot
replicate unless inside a living host cell. A virus depends on its living host to provide the
framework to replicate.
, Describe the basic steps of the viral life cycle. - CORRECT ANSWER - 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
3. Uncoating: (where applicable) the viral capsid disassembles
4. Replication: The viral genome provides the 'blueprint' to make copies of itself
5. Exit: New viruses are produced and leave the cell
6. New infection: Newly produced viruses leave the host cell and go on to infect new cells. The
process outlined above now restarts.
What is a bacteriophage? - CORRECT ANSWER - A virus that infects bacteria
What structural aspects make bacteriophages distinct from viruses that infect either animals or
plants? - CORRECT ANSWER - They have an icosahedral capsid head and a helical tail.
Which viral replicative process results in the destruction of the host cell? - CORRECT
ANSWER - The lytic replication cycle
Describe the appearance of a bacterial culture infected with virus at the time of infection versus
later once viral replication is occurring at a high rate. - CORRECT ANSWER - It turns
from a turbid to clear, the bacterial cell numbers decrease due to lysis and the media becomes
clearer.
To what family of viruses does rubella come from and how is it transmitted? - CORRECT
ANSWER - Rubella comes from Togaviridae and it is transmitted by air-borne particles.
What is the common name for rubeola, and is it a DNA or RNA virus? - CORRECT
ANSWER - It is commonly known as measles and belongs to viruses called
Paramyxovirus. It is a RNA.
What disease state emerges as a viral reactivation of a prior infection with the varicella virus? -
CORRECT ANSWER - Shingles, also known as Herpes zoster, is due to the reactivation
of the varicella-zoster virus (VZV). Because VZV lies dormant in inactive nerve cells, its
