B5 | health & disease

Question 1

lytic cycle steps

Answer 1

1. virus attaches to a host cell
2. virus injects viral DNA into the cell
3. viral DNA replicates within the cell
4. viral DNA components join together to create new viruses
5. lysis occurs (cell bursts)
6. process repeats

Question 2

lysogenic cycle steps

Answer 2

1. virus attaches to host cell
2. virus injects viral DNA into cell
3. cell divides which clones the viral DNA
4. viral DNA joins to form new viruses
5. lysis occurs
6. process repeats

Question 3

how do bacteria become resistant to antibiotics?

Answer 3

1. bacteria reproduces at a rapid rate
2. due to mutation, new genes are created for the bacteria which contains characteristics that are resistant to antibiotics
3. exposure to antibiotics creates a “survival of the fittest” situation; bacteria with mutated genes survive while bacteria without the genes die out
4. the bacteria containing the mutated gene then reproduce and pass this trait to their offspring
5. popularity of bacteria with mutated gene increases until all bacteria are resistant to the antibiotics

Question 4

what are statins?

Answer 4

drugs which reduce blood cholesterol which prevents atherosclerotis/heart disease by reducing liver’s production of cholesterol

Question 5

what are anticoagulants?

Answer 5

drugs which treat blood clots by preventing the clot from getting bigger while your body slowly reabsorbs it

Question 6

how do stents work?

Answer 6

stent is placed in artery by a catheter, the balloon is inflated which expands the stent, then the balloon and catheter are removed leaving the stent open

this widens the artery which improves blood flow and allows more oxygen to be delivered to organs

Question 7

how is cholera transmitted?

Answer 7

contaminated food and water

Question 8

symptoms of cholera

Answer 8

dehydration, diarrhea

Question 9

how is tuberculosis transmitted?

Answer 9

via airborne water droplets (sneezing, coughing, speaking etc)

Question 10

how is helicobacter transmitted?

Answer 10

contaminated food and water

Question 11

what does helicobacter cause?

Answer 11

stomach ulcers which leads to pain, nausea and vomiting

Question 12

how is ebola transmitted?

Answer 12

through bodily fluids

Question 13

how do antibiotics work?

Answer 13

by inhibiting processes in bacterial cells

some inhibit the building of bacterial cell walls which prevents them from dividing and kills them

some inhibit protein synthesis

Question 14

can antibiotics damage human cells?

Answer 14

no because human cells have no cell walls, and antibiotics work by targeting and inhibiting the growth of bacterial cell walls

Question 15

advantage and disadvantage of testing new medicines of human tissue

Answer 15

• no harm or side affects to living humans

- doesn’t show the effects on other parts of the body systems

Question 16

steps in developing new medicines:

Answer 16

stage 1 = discovery

stage 2a = pre clinical testing
(testing on human tissue and live animals)

stage 2b = clinical testing
(1. test on healthy volunteers of similar age and gender

2. test on unhealthy volunteers with the illness that the drug is for
   3a. blind trials where one half given real drug and other half given placebo
   3b. double blind trials where neither patient nor doctor know which drug is real and which is the placebo