A
1. Substitution
2. insertions
3. deletions
what is broad tropism?
A virus with a large variety of infectable hosts.
How do naked viruses occur?
what is narrow tropism
A disease with a small range of hosts that are infectable.
What does viral genome code for?
It encodes a minimal set of proteins that are needed to hijack host cells and make new virus.
What is the difference between bacteriophages and animal viruses
Bacteriophages infect and destroy bacteria.
Animal viruses infect eukaryotic cells.
List the 3 different shapes of capsids
1. Helical capsids
2. Icosahedral (polyhedral) capsids
3.Complex capsids
How do enveloped viruses occur
enveloped viruses come from the host cell's membrane during the budding process.
Why is DNA replication continuous on the leading strand?
DNA can only be built in the 5' to 3' direction. the lagging strand runs 3' to 5
What is the function of spikes (peplomers)
They assist in attachment to hosts, entry, and specify hosts.
They also become a target for an organisms immune system.
Explain how viral mutations effect a virus.
1.Increase speed of spreading
2. More infectious
3. Drug resistance
4. Immune system evasion
5. New host infectability
How are viral strains created?
Swapping genetic material when multiple viruses infect the same host, or copying errors during replication.
Why do viruses exhibit a faster rate of genomic change than other living infectious agents?
Their replication enzymes lack proofreading mechanisms
What kind of diseases do prions cause?
Prion diseases are rare, progressive and fatal neurodegenerative conditions
Which DNA sequence can change its position with a genome?
Transposons. also known as "jumping genes"
What is phage conversion?
List the 3 steps of transcription in prokaryotes.
1. Initiation
2.Ellongation
3.Termination
List the 4 steps of transcription in eukaryotic cells
1.Initiation
2.Ellongation
3.Termination
4. post-transcript modification.
What kind of effects do spongiform encephalopathies have on the human body?
Brain tissue deterioration.
How does genotype effect phenotype?
Genotype is the fundamental blueprint for an organism, and phenotype is the visible result of the genotypes blueprint.
what 4 properties are used to classify viruses?
1. Type of nucleic acid (DNA or RNA)
2.Capsid symmetry (helical, Icosahedral, or complex.)
3.Presence or absence of an envelope
4. Genome architecture (ssDNA, ssRNA, ect.)
What is the highest taxon level for viruses?
What are the 5 steps of the Lytic replication pathway
1. Attachment(absorption)
2.Entry
3.Replication
4.Assembly (maturation)
5.Lysis (release)
What are the 4 steps in Lysogenic replication.
1.Attachment
2.Integration
3.Passive replication
4.induction and switching to lytic cycle
What are the 6 steps of replication for animal viruses?
1.Attachment
2.Penitration
3.Uncoating
4.Synthesis
5.Assembly (maturation)
6.Release via budding