BIOD 171 MODULE 6 REVIEW
QUESTIONS 100% CORRECT RATED A+
Can viruses be classified as either prokaryotic or eukaryotic microorganisms?
✔✔No — Viruses do not fall into either category because they are not made of
cells and are not considered living organisms.
What is an obligate intracellular parasite?
✔✔This term refers to organisms like viruses that must enter a living host cell to
reproduce. They rely entirely on the host's cellular machinery to produce new viral
particles.
What is a viral capsid?
✔✔A capsid is the protein shell that encases and protects a virus’s genetic
material. It functions like a container, somewhat similar to how the nucleus
protects DNA in a eukaryotic cell, but it is not membrane-bound.
What is the viral envelope, and what does the presence (or absence) of it tell you
about the type of virus?
The envelope surrounds the viral capsid, is derived from the host cell membrane
and serves as an additional barrier to the external environment. The overwhelming
majority of animal viruses are enveloped whereas the majority of plant or bacteria-
infecting viruses are not.
What type of microscope would be used to study the shape of a viral capsid?
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?
The viral envelope contains the necessary proteins required for interaction with
host cells. As the envelope is derived from the host cell membrane, this
camouflages the virus and lowers the likelihood of immune detection by making it
appear similar to the normal biological host cell.
What must happen before viral replication of its genome can occur?
For all viruses, the genome is replicated following attachment and entry, never
before.
Describe the basic steps of the viral life cycle.
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?
A bacteriophage is simply a virus (phage) that infects bacteria.
QUESTIONS 100% CORRECT RATED A+
Can viruses be classified as either prokaryotic or eukaryotic microorganisms?
✔✔No — Viruses do not fall into either category because they are not made of
cells and are not considered living organisms.
What is an obligate intracellular parasite?
✔✔This term refers to organisms like viruses that must enter a living host cell to
reproduce. They rely entirely on the host's cellular machinery to produce new viral
particles.
What is a viral capsid?
✔✔A capsid is the protein shell that encases and protects a virus’s genetic
material. It functions like a container, somewhat similar to how the nucleus
protects DNA in a eukaryotic cell, but it is not membrane-bound.
What is the viral envelope, and what does the presence (or absence) of it tell you
about the type of virus?
The envelope surrounds the viral capsid, is derived from the host cell membrane
and serves as an additional barrier to the external environment. The overwhelming
majority of animal viruses are enveloped whereas the majority of plant or bacteria-
infecting viruses are not.
What type of microscope would be used to study the shape of a viral capsid?
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?
The viral envelope contains the necessary proteins required for interaction with
host cells. As the envelope is derived from the host cell membrane, this
camouflages the virus and lowers the likelihood of immune detection by making it
appear similar to the normal biological host cell.
What must happen before viral replication of its genome can occur?
For all viruses, the genome is replicated following attachment and entry, never
before.
Describe the basic steps of the viral life cycle.
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?
A bacteriophage is simply a virus (phage) that infects bacteria.
