Week 1

Question 1

What is a Plaque assay?

Answer 1

• uses a petri dish of inoculated bacteria in which dilution of phage suspension are placed, the phages the lead to clear spot within thick bacterial colony
• allows scientist the ability to count number of infectious virus particles in a suspension with high precision

Question 2

What are the general steps in virus replication?

Answer 2

1) Binding to cell receptor
2) Entry and uncoating
3) Early gene expression
4) Replication of viral genome
5) Late gene expression
6) Assembly of virions

Question 3

What are the seven groups in Balitmore Virus classification system?

Answer 3

1) positive-strand RNA genome
2) negative-strand RNA genome
3) viruses with double-stranded RNA genomes
4) viruses with single-stranded DNA genomes
5) viruses with double stranded DNA genomes
6) viruses that use reverse transcriptase
7) satellite viruses, nucleic acids, and viroid

Question 4

What does the virus envelope (if applicable) consist of?

Answer 4

• lipid membrane that encloses the nucleocapsid
• contain viral glycoproteins inserted into the lipid membrane
• most formed by budding from preexisting cellular membrane
• matrix protein, a layer some virions have between the nucleoplasm and the envelope