RNA Viruses 1

Question 1

High Mutation rates in viruses results in…

Answer 1

Resistance to antivirals
Barriers to vaccines
Reassortment of genome segments

Question 2

Common features of RNA viruses

Answer 2

1. RNA is the genetic material and the template for protein synthesis
2. Replication serves to copy genome and make mRNA

Question 3

What is the sense and antisense strand?

And which one is the template strand?

Answer 3

Sense= (+) strand = mRNA
Antisense= (-)= Template for mRNA

Question 4

Where does RDRP do its job?

High or low fidelity?

Answer 4

Cytoplasm
Often on a membrane
This concentrates all the components and increases efficiency
Low (no proofreading)

Question 5

Ways RNA viruses create genetic diversity

and the consequences of this

Answer 5

Recombination
Reassortment
Consequences: mutations arise frequently, which may cause new disease and lose of effectivity of vaccines and treatments

Question 6

Polio:

1. genome type
2. Transmission
3. Pathogenesis
4. Diagnosis
5. Treatment
6. Prevention

Answer 6

1. (+)ssRNA, linear mRNA molecule
2. fecal-oral; persists in H2O
3. 95% asymptomatic acute GI infection
4. Motor neural involvement and serology/culture
5. Control symptoms and breathing support
6. Vaccine and Sanitization

Question 7

Polio life cycle

Answer 7

Binds membrane protein then changes to hydrophobic caspid protein which forms a pore and RNA genome enters
Translation of RNA occurs first until enough RDRP is produced then replication occurs
When enough caspid proteins accumulate new mRNA is packaged instead of translated

Question 8

When is RDRP present in virion

Answer 8

All RNA viruses encode for RDRP
(-) RNA and ds RNA must be packages with a RDRP
(+) can be but doesn’t need to have one (if it doesn’t have one pre made then translation of this protein is the first step once in a host cell)