Microbiology Exam 6 Portage Learning
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.(Ans- 1) Genomic material made up of DNA or RNA 2) Capsid, which is a membrane like protective structure that contains genetic material.
The ________ surrounds the capsid of some viruses.(Ans- envelope
Rank the falling viruses from smallest to largest:
Poliovirus Variola virus Orthomyxovirus (Ans- Variola virus Orthomyxovirus Poliovirus
True or False: Viral replication occurs after it attaches and enters the host
cell.(Ans- True
True or False. You would expect to see a viral envelope on a virus infecting a bacterial cell.(Ans- False. The 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 / 2
Paramyxovirus Polivirus Smallpox virus (Ans-
1 (Largest): Smallpox
2: Paramyxovirus
3 (Smallest): Poliovirus
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.
Uncoating:
Release:
Replication:
Attachment:
Entry:
New infection:
(Ans-
1) Viral Attachment: Virus particle attaches to surface of host's cell
2) Entry: Virus fuses with host membrane and enters cell
3) Uncoating: once viral genetic material is inside host's cell, envelope will
shed releasing genetic material (disessembles)
4) Replication: Viral genetic material replicates and new viral proteins are
made
5) Release: New viruses produced & leave host cell
6) New Infection: Newly released virus particles find a new host cell to
infect (continuing process)
A virus that infects bacteria is called a [answer1] and contains a [answer2] - sided polygon capsid.(Ans- Bacteriophages 20
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