Supplementary Lectures

Question 1

what is genomic drift

Answer 1

where the haemagglutinin of the virus changes slightly but is still recognisable

Question 2

What are the steps of a haemagglutination inhibition assay

Answer 2

1. Virus binds to RBCs 2. Specific antibodies prevent shield forming 3. Virus cannot cross link with RBC when antibody bound 4. RBC fall to the bottom of the well- button

Question 3

What are the steps of a haemagglutination assay

Answer 3

1. Virus binds to RBCs 2. Cells fall to the bottom of the wells due to gravity 3. Sialic acids bound to by virus, forming a shield at the well bottom 4. Perform serial dilution 5. The last well with a shield means you can calculate the virus titre

Question 4

Explain the stages of viral replication

Answer 4

1. virus adheres to cell surface 2. virus enters cell by pinocytosis 3. virus sheds coat 4. replication of viral nucleic acids 5. synthesis of viral protein of capsid 6. assembly of new virions 7. release of virus

Question 5

What is a plaque assay

Answer 5

used to purify a clonal population of virus or to determine viral titer

Question 6

What is the end-point of the assay

Answer 6

1/512

Question 7

What is would a positive result of a haemagglutination inhibition assay show

Answer 7

button

Question 8

What is the baltimore classification system

Answer 8

How viruses nucleic acids make mRNA

Question 9

Would genomic drift or shift be more likely to cause a pandemic

Answer 9

Shift

Question 10

What can viruses be classified based on

Answer 10

• Size, shape (helical, icosahedral, complex) • Type of nucleic acid in the genome (No strands/Sense) • How they produce mRNA

Question 11

What strain of influenza is Patient ‘JB’ was infected by

Answer 11

H1 strain of influenza

Question 12

What does neuraminidase facilitate

Answer 12

the release of the virus from infected host cells

Question 13

What do viruses contain

Answer 13

• A Nucleic acid – RNA or DNA • Viral proteins on their surface • Nucleocapsid- forms shape • Lipid envelope- usually originates from host cell

Question 14

True or false: Viruses are visible under a light microscope

Answer 14

False

Question 15

Why can sense RNA viruses not act as an RNA template

Answer 15

risk of mutation

Question 16

What is genomic shift

Answer 16

when the haemagglutinin of the virus changes completely

Question 17

Explain the steps of a plaque assay

Answer 17

10-fold dilutions of a virus stock are prepared, and 0.1 ml aliquots are inoculated onto susceptible cell monolayers. Monolayers are covered with a nutrient medium containing agar original infected cells release viral progeny. each infectious particle produces a circular zone of infected cells called a plaque. Eventually the plaque becomes large enough to be visible to the naked eye.

Question 18

How many groups are there in the baltimore classification system

Answer 18

7

Question 19

What can be used to subtype viruses

Answer 19

neuraminidases

Question 20

what is qt-PCR

Answer 20

the RNA in the virus is converted to CDNA which then gets amplified. It monitors the amplification in real-time

Question 21

What does haemagglutinin facilitate?

Answer 21

entry of the virus into host cells (binds to sialic acid)

Question 22

What is would a positive result of a haemagglutination assay show

Answer 22

a shield