MODULE 6 EXAM 100% VERIFIED
2025
, Can viruses be classified as either prokaryotic or eukaryotic? - ANSWERNo. Viruses
are neither prokaryotic nor eukaryotic.
What is an obligate intracellular parasite? - ANSWERViruses cannot replicate unless
inside a living host cell. A virus depends on its living host to provide the framework to
replicate.
What is a viral capsid? - ANSWERThe capsid is a membrane-like protective structure
that contains the genetic material, similar to the nucleus of a eukaryotic cell.
What is the viral envelope, and what does the presence (or absence) of it tell you about
the type of virus? - ANSWERThe 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? -
ANSWERDue 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? - ANSWERIt 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? - ANSWERThe
genome is replicated following attachment and entry
Describe the basic steps of the viral life cycle. - ANSWER1. 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? - ANSWERA virus that infects bacteria
What structural aspects make bacteriophages distinct from viruses that infect either
animals or plants? - ANSWERThey have an icosahedral capsid head and a helical tail.