BIOD 171 EXAM
MODULE 6
. True or False. Because the genome is contained within an enclosed space, (much like the nucleusof a
cell) viruses are classified as eukaryotic.
False. Viruses are neither eukaryotic nor prokaryotic.
2. 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 nucleusof a eukaryotic cell.
Exam Page 2
Answer Key
1. The surrounds the capsid of some viruses.
Envelope.
2. 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 ofplant or
bacteria-infecting viruses are not.
3. Rank the following viruses based on their size from largest to smallest:
Orthomyxovirus
Exam Page 3
Poliovirus
Variolavirus
Variolavirus (~200nm) > Orthomyxovirus (100-150nm) > Poliovirus (~30nm)
, Attachment: The virus receptors binds to the host protein outside the cell
Entry: The virus joins with the membrane of host & enters cell
Uncoating: The viral capsid is pulled apart where applicable.
Replication: The viral genome makes copies of itself
Exit: Old virus leaves the cell & new viruses are produced
New infection: New viruses produced leaves the host cell & go infect new cells. This process
restarts
Answer Key
1. 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.
True. The viral genome is never replicated before attachment and entry.
2. Place the following viral life cycle steps in order beginning with viral attachment and provide a
description of each step.
Uncoating:
Release:
Replication:
Attachment:
Entry:
New infection:
Exam Page 4
3- Uncoating: the viral capsid disassembles
Answer Key
5-Release: New virus particles are produced and leave the cell
1. A virus that infects bacteria is called a and contains a -side polygon capsid.
4-Replication: the viral genome is the ‘blueprint’ to make copies of itself
1-Attachment:
Bacteriophage;viral receptors bind to host proteins on the surface of the cell2-Entry:
20-sided
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.
2. True or False. Structurally, bacteriophages are similar to viruses that infect animals.
False. Bacteriophages have a distinct composition and structure.
3. Identify the following components of a bacteriophage.
MODULE 6
. True or False. Because the genome is contained within an enclosed space, (much like the nucleusof a
cell) viruses are classified as eukaryotic.
False. Viruses are neither eukaryotic nor prokaryotic.
2. 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 nucleusof a eukaryotic cell.
Exam Page 2
Answer Key
1. The surrounds the capsid of some viruses.
Envelope.
2. 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 ofplant or
bacteria-infecting viruses are not.
3. Rank the following viruses based on their size from largest to smallest:
Orthomyxovirus
Exam Page 3
Poliovirus
Variolavirus
Variolavirus (~200nm) > Orthomyxovirus (100-150nm) > Poliovirus (~30nm)
, Attachment: The virus receptors binds to the host protein outside the cell
Entry: The virus joins with the membrane of host & enters cell
Uncoating: The viral capsid is pulled apart where applicable.
Replication: The viral genome makes copies of itself
Exit: Old virus leaves the cell & new viruses are produced
New infection: New viruses produced leaves the host cell & go infect new cells. This process
restarts
Answer Key
1. 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.
True. The viral genome is never replicated before attachment and entry.
2. Place the following viral life cycle steps in order beginning with viral attachment and provide a
description of each step.
Uncoating:
Release:
Replication:
Attachment:
Entry:
New infection:
Exam Page 4
3- Uncoating: the viral capsid disassembles
Answer Key
5-Release: New virus particles are produced and leave the cell
1. A virus that infects bacteria is called a and contains a -side polygon capsid.
4-Replication: the viral genome is the ‘blueprint’ to make copies of itself
1-Attachment:
Bacteriophage;viral receptors bind to host proteins on the surface of the cell2-Entry:
20-sided
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.
2. True or False. Structurally, bacteriophages are similar to viruses that infect animals.
False. Bacteriophages have a distinct composition and structure.
3. Identify the following components of a bacteriophage.
