Portage Microbiology
True or False: Because the genome is contained within an enclosed space, (much like the
nucleus of a cell) viruses are classified as eukaryotic - ANS False. Viruses are neither
eukaryotic nor prokaryotic
Describe the two basic components of a virus (short answer) - ANS 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 - ANS Envelope
The envelope surrounds the _____ of some viruses - ANS Capsid
True or False: You would expect to see a viral envelope on a virus infecting a plant cell - ANS
False. The overwhelming majority of animal viruses are enveloped whereas the majority of plant
or bacteria-infecting viruses are not
True or False: You would expect to see a viral envelope on a virus infecting a bacterial cell -
ANS False: Not all the viruses have envelopes
Rank the following viruses based on their size from largest to smallest: orthomyxovirus,
poliovirus, variolavirus - ANS Variolavirus>Orthomyxovirus>Poliovirus
Rank the following viruses based on their size from largest to smallest:Paramyxovirus,
Poliovirus, Smallpox virus - ANS Smallpox>Paramyxovirus>Poliovirus
True or False: Viral replication occurs after it attaches and enters the host cell - ANS True. The
viral genome is never replicated before attachment and entry
True or False: Highly infectious viruses undergo genome replication prior to viral attachment and
entry. - ANS False. The viral genome is never replicated before attachment and entry
regardless of its level of infectivity.
Place the following viral life cycle steps in order beginning with viral attachment and provide a
description of each step (short answer) - ANS Uncoating: the viral capsid disassembles
Release: New virus particles are produced and leave the cell
Replication: the viral genome is the 'blueprint' to make copies of itself
Attachment: viral receptors bind to host proteins on the surface of the cell
Entry: the virus fuses with the host membrane and enters the cell
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 (fill in
the blank) - ANS Bacteriophage; 20-sided
True or False: Structurally bacteriophages are similar to viruses that infect animals - ANS
False. Bacteriophages have a distinct composition and structure
True or False. Structurally, bacteriophages are distinct from viruses that infect plant or animal
cells. - ANS True. Bacteriophages are structurally distinct from viruses that infect plant and
animals cells.
Identify the following components of a bacteriophage (picture) - ANS 1. Capsid
2. Collar
3. Tail
4. Base
5. Tail fibers
True or False: Because the genome is contained within an enclosed space, (much like the
nucleus of a cell) viruses are classified as eukaryotic - ANS False. Viruses are neither
eukaryotic nor prokaryotic
Describe the two basic components of a virus (short answer) - ANS 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 - ANS Envelope
The envelope surrounds the _____ of some viruses - ANS Capsid
True or False: You would expect to see a viral envelope on a virus infecting a plant cell - ANS
False. The overwhelming majority of animal viruses are enveloped whereas the majority of plant
or bacteria-infecting viruses are not
True or False: You would expect to see a viral envelope on a virus infecting a bacterial cell -
ANS False: Not all the viruses have envelopes
Rank the following viruses based on their size from largest to smallest: orthomyxovirus,
poliovirus, variolavirus - ANS Variolavirus>Orthomyxovirus>Poliovirus
Rank the following viruses based on their size from largest to smallest:Paramyxovirus,
Poliovirus, Smallpox virus - ANS Smallpox>Paramyxovirus>Poliovirus
True or False: Viral replication occurs after it attaches and enters the host cell - ANS True. The
viral genome is never replicated before attachment and entry
True or False: Highly infectious viruses undergo genome replication prior to viral attachment and
entry. - ANS False. The viral genome is never replicated before attachment and entry
regardless of its level of infectivity.
Place the following viral life cycle steps in order beginning with viral attachment and provide a
description of each step (short answer) - ANS Uncoating: the viral capsid disassembles
Release: New virus particles are produced and leave the cell
Replication: the viral genome is the 'blueprint' to make copies of itself
Attachment: viral receptors bind to host proteins on the surface of the cell
Entry: the virus fuses with the host membrane and enters the cell
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 (fill in
the blank) - ANS Bacteriophage; 20-sided
True or False: Structurally bacteriophages are similar to viruses that infect animals - ANS
False. Bacteriophages have a distinct composition and structure
True or False. Structurally, bacteriophages are distinct from viruses that infect plant or animal
cells. - ANS True. Bacteriophages are structurally distinct from viruses that infect plant and
animals cells.
Identify the following components of a bacteriophage (picture) - ANS 1. Capsid
2. Collar
3. Tail
4. Base
5. Tail fibers
