past general

Question 1

True/false: Prions are resistant to proteases

Answer 1

True

Question 2

Prion pathogens do not contain?

Answer 2

Nucleic acid (proteins)

Question 3

Affinity Chromatography uses?

Answer 3

Viruses adsorb to specific antibodies, rinsing to remove impurities and then elution with buffer.

Question 4

Which disease was recently eradicated from earth?

Answer 4

Small pox and rinderpest

Question 5

How did virus get its name?

Answer 5

A scientist used a filter whose pores were smaller than the bacteria so the bacteria was not filtered, but following further investigation, it was found that the filtrate contained a smaller form of infectious agent. This agent multiplies only in dividing cells and it was made of particles – it was called contagium vivum fluidum (soluble living germ) and later was simply called virus.

Question 6

How are airborne viruses contracted?

Answer 6

Breathed in through the respiratory tract.

Question 7

What is the given name for Goose Disease?

Answer 7

Goose Parvovirus (Derzsy’s Disease)

Question 8

What virus is propagated in the Chorioallantoin?

Answer 8

Pox and Herpesvirus

Question 9

What is eclipse?

Answer 9

Eclipse is the expression of genetic information. It is the step in virus multiplication involving transcription, translation and replication.

Question 10

Genetic part of a virion?

Answer 10

DNA/RNA

Question 11

The role of Rdrp in Retrovirus?

Answer 11

(RNA Dependent RNA Polymerase) Replication of RNA.

Question 12

57. How do bacteriophages get into the host cell?

Answer 12

Penetration.

Question 13

What is a prion?

Answer 13

A prion is a small protein capable of infecting a cell and causing itself to replicate even though it contains no nucleic acid.

Question 14

True/false:

Virions always contain lipids.

Answer 14

FALSE

Question 15

True/false:

Virions with quasihelical nucleocapsids are enveloped.

Answer 15

true

Question 16

Ture/false:

Virions with quasihelical capsids are never enveloped.

Answer 16

false

Question 17

True/false:

Pleomorphic capsids may not have an envelope.

Answer 17

true

Question 18

Please mark which is true:

a) Mutations are more frequent in cellular organisms than in viruses
b) The effects of mutations are always advantageous for viruses
c) Mutation may alter the host specificity of a virus
d) Mutant viruses cannot be used as vaccine strains.

Answer 18

c) Mutation may alter the host specificity of a virus

Question 19

How do we call the process when the antigenic structure of a virus suddenly changes due to reassortment?

Answer 19

Antigenic shift.

Question 20

How does the enveloped virus enter the cell?

Answer 20

Membrane fusion

Question 21

True/false:

Viruses can only propagate in living cells.

Answer 21

True

Question 22

Contact Inhibition:

Answer 22

When the cytoplasmic membrane edges of growing cells touches each other causing an inhibition to growth (forms a primary monolayer of cells)

Question 23

What do you call the infective part of the virus?

Answer 23

Virion

Question 24

Where do RNA viruses multiply?

Answer 24

In the cytoplasm

Question 25

How to investigate virus neutralisation test?

Answer 25

Use blocking antibodies that will adsorb to the receptors of the cell so virus cant adsorb to the cell too. - Constant virus varying serum dilution: Serial 2fold serum solution, add virus, incubate (antibodies will neutralise the virus), inoculate cell cultures, incubate, CPEs. - Constant serum varying virus dilution: 2 Serial 10fold virus dilutions, add +and-serum, incubate, inoculate cell cultures, incubate, CPEs.

Question 26

Monoclonal antibodies

Answer 26

Antibodies which are the same as they were produced by identical immune cells who were all clones of a unique parent cell.

Question 27

What proteins are found in prions?

Answer 27

Cellular prion protein, Infectious prion protein.

Question 28

What is the genetic part of the virion?

Answer 28

The nucleic acid (DNA/RNA)

Question 29

Haemagglutination:

Answer 29

This is the clumping together of red blood cells. Tests include: Haemagglutination test, haemagglutination inhibition test.

Question 30

Concentration of a virus sample?

Answer 30

Precipitation, adsorption, dialysis, ultrafiltration, pelletisation.

Question 31

Virus titer:

Answer 31

- Infective titer: the highest dilution of the virus in which 50% CPEs occur. - Haemagglutination titer: the highest dilution of the virus in which haemagglutination has not yet occurred.

Question 32

Restriction nucleases:

Answer 32

cleave proteins at specific DNA sequences.

Question 33

Cells removed from a monoculture:

Answer 33

Can then be used in a subculture and propagated further.

Question 34

What type of sample is required for Ataxia in a horse?

Answer 34

Conjunctival and nasal swabs, liquor cerebrospinalis, EDTA blood. (Ataxia is a neurological sign consisting of a lack of coordinating movements)

Question 35

Propagation of African Swine Fever:

Answer 35

experimental infection of living animals

Question 36

Acridin Orange Test:

Answer 36

Tests for the presence of either ss/ds DNA/RNA. -Green fluorescence when bound to dsDNA. –Red fluorescence when bound to ssDNA or RNA.

Question 37

Does a greenish-yellow colour mean a doublestranded virus?

Answer 37

Yes

Question 38

Vaccines:

Answer 38

Live (attenuated, virulent, heterotypic, virus-vectored), inactivated, subunit, anti-idiotype.

Question 39

Active Immunity:

Answer 39

Stimulation of an immune response by the body by a specific antigen (injecting a weaker live virus into the body so that the body itself must produce antibodies against the viral antigens), preventative method, long term immunity.

Question 40

On which part of the virus is the lipid found?

Answer 40

Envelope.

Question 41

PCR-Colour:

Answer 41

Green-dsDNA, | Red-ssDNA/RNA

Question 42

What is the method of a hemolysis test using sheep blood?

Answer 42

- Haemagglutination Titre: serial 2fold dilution, add washed RBCs of appropriate species, incubate->titer is the highest dilution of virus where there is no haemagglutination as of yet. - Haemagglutination inhibition: serial 2fold dilution of serum sample, add 4-8HA units of virus, incubate, add washed RBCs->titer is the highest dilution where there is no HA.

Question 43

Amino Acid sequence of haemagluttinating protease cleavage site of Influenza A may cause?

Answer 43

Will cleave the Hemaglutinin of the virus-this must be cleaved by cellular proteases to be active as a fusion protein and cause infection.