L23 Viruses and Diseases

Question 1

types of infection

Answer 1

acute
persistant
transformative

Question 2

types of persistant infection

Answer 2

latent

chronic

Question 3

characteristics of acute infection

Answer 3

short incubation
host cell dies
clinical symptoms present
virus is cleared quickly from host

Question 4

characteristics of persistent infection

Answer 4

long incubation period

can persist for life

Question 5

what occurs during latent infection

Answer 5

progeny are not produced, few proteins and genome is present

no clinical symptoms

Question 6

what is meant by chronic infection

Answer 6

progeny are produced, and can be passed to offspring

symptoms present

Question 7

what can a latent infection turn into and how

Answer 7

acute infection

stress and hormonal changes can trigger it

Question 8

what is transformative infection

Answer 8

causes cells to become cancerous

Question 9

what are cancer causing genes called?

Answer 9

viral oncogenes

Question 10

how do viral oncoproteins cause cells to become cancerous

Answer 10

1. inactivate host tumour suppresser proteins
2. hyperactivity host proto-oncogenes
   both result in uncontrolled cell division

Question 11

what happens to the host cell in the lytic cycle and lysogenic cycle

Answer 11

lytic = death
lysogenic = survives

Question 12

what kinds of viruses follow a lytic cycle

Answer 12

virulent phage

-T4 bacteriophage

Question 13

what kind of viruses follow a lysogenic cycle

Answer 13

temperate (slightly subdued) phage

-lambda phage

Question 14

in lysogeny what is the host bacterium referred to as

Answer 14

lysogen

Question 15

what form of the phage remains in the lysogen

Answer 15

prophage (viral genome)

Question 16

how is the prophage present in the lysogen

Answer 16

integrated into the lysogen genome

Question 17

what is lysogenic conversion

Answer 17

when the prophage changes the lysogen phenotype

Question 18

use Diptheria as an example of lysogenic conversion

Answer 18

C. diphtheria only causes diptheria when in lysogeny, the prophage encodes for the toxin

Question 19

Use salmonella as an example of lysogenic conversion

Answer 19

prophages remove the receptor on salmonella to make it immune to superinfection

Question 20

what causes the induction of a temperate phage to become a virulent phage

Answer 20

growth conditions

UV irridation

Question 21

five ways of viral transmission

Answer 21

aerosol
faecal-oral
blood, semen
zoonotic
vecters

Question 22

what is the aerosol transmission

Answer 22

respiratory droplets and secretions

Question 23

what is feacel-oral transmission

Answer 23

contamination of water/ food

Question 24

what is transmission of direct contact with bodily fluids caused by

Answer 24

contact with blood, semen

Question 25

what causes zootonic transmission

Answer 25

direct contact with an infected animal

Question 26

what is vector transmission caused by

Answer 26

vectors (insects, nematodes)

Question 27

five categories of viral diseases

Answer 27

``` air-borne diseases food and water-borne diseases Direct contact zootonic anthropod-borne ```

Question 28

examples of airborne diseases

Answer 28

``` Flu chicken pox measles mumps rubella smallpox covid ``` these are the disease not the viruses

Question 29

examples of food-water borne diseases

Answer 29

viral gastrointendinitis viral hepatitis poliomyelitis these are the diseases not the viruses