Clickers Flashcards
Why do viruses that are good replicators not kill their host?
- They have co-evolved for a long time
- They want to use the host but not kill them
- They can evade the host’s immune response
- all of the above
What technology was essential for helping scientists first identify viruses?
electron microscopy
What did Jesse Lazear determine was the vector for yellow fever?
mosquitos
What kind of morphology does adenovirus have?
Icosahedral capsid, non-enveloped
Bacterial genomes are all larger than virus genomes
false
A larger genome means a more complex virus
true
What is NOT a strategy that viruses use to maximize efficiency of their genomes?
phosphorylation
In viral taxonomy a virus family ends in…
Viridae
You can classify viruses based on their
all of the above
structure, genome type, genome sequence
The definition for species is the same for animals and viruses.
false
What is a satellite virus?
A virus that can’t replicate without a helper virus
What about hepatitis delta virus makes it like a viroid?
RNA genome with complex secondary structure
What is a concatamer?
A circular genome copied many times
Despite its size relative to other viruses, Mimivirus is still smaller than the smallest bacteria.
false
Creutsfeldt-Jacob disease can be inherited (familial) or contracted from consumption of contaminated tissue. What zoonotic disease was initially considered the source of BSE?
scrapie
Cell tropism
- Indicates what cell types a virus will infect
- Is dictated by the molecules expressed on the surface of the cell
- Is dictated by the molecules expressed on the surface of the virus
- all of the above
Which virus has a promiscuous cell tropism?
herpes simplex virus
How does an enveloped virus enter a cell?
- fusion with the cell membrane
- entry via acidification within a vesicle
How does influenza virus use acidification of the endosome to enable entry?
- changes HA molecule to allow fusion of viral envelope with the endosomal membrane
- changes M1 so it dissociates from genomic RNA
Small DNA viruses replicate their genomes:
in the nucleus
How does a virus get its genome into the nucleus?
- Small enough to transport whole virion through the nuclear pore
- Bind to nuclear pore and inject genome through and into nucleus
- Genome alone enters nucleus through pore
- Enter nucleus during mitosis and nuclear envelope degradation
- all of the above
Which of the following describes the temporal regulation of HSV-1 replication?
- Non-structural proteins are made first
- Early proteins are involved in replicating the genome
- Genes are transcribed in three distinct phases
- all of the above
What polymerase do ssDNA viruses use to copy their genomes?
Host-encoded DNA dependent RNA polymerase
Which virus genome would be considered infectious?
+ ssRNA
What phospholipid bilayer is used by viruses for their envelope?
- Plasma membrane
- Nuclear membrane
- ER membrane
- Golgi membrane
- all of the above
