12.7 Preventing & Treating Disease

Question 1

What are the 2 types of adaptive immunity

Answer 1

naturally acquired and artificially acquired

Question 2

What are the 2 types of naturally acquired immunity

Answer 2

active and passive

Question 3

What’s naturally acquired ACTIVE immunity

Answer 3

antigens enter the body naturally; body induces antibodies and specialised lymphocytes

Question 4

What’s naturally acquired PASSIVE immunity

Answer 4

antibodies pass from mother to foetus via placenta or through breastmilk

Question 5

What is natural immunity in babies (PASSIVE)

Answer 5

Some antibodies are passed through the placenta but most are passed in the colostrum (first milk a mammalian mother makes). It’s extremely high in antibodies and strengthens the baby’s immune system to be as good as the mother’s.
Antibodies are absorbed into bloodstream in the gut.

Question 6

What are the 2 types of artificial immunity

Answer 6

active and passive

Question 7

What’s PASSIVE artificial immunity

Answer 7

For some fatal diseases, antibodies can be made by one individual, extracted and inserted in the blood of someone else.
Doesn’t last long but can be life saving.
Examples are tetanus, rabies. Could work for COVID.

Question 8

What’s ACTIVE artificial immunity

Answer 8

When the immune system is stimulated to make its own antibodies to a safe form of the antigen. The antigen is not normally from a ‘live’ pathogen as this could be harmful.
Called a VACCINATION

Question 9

What are the differences between active and passive immunity

Answer 9

1. active requires exposure to antigens, passive doesn’t
2. active takes a while for protection to develop, passive is immediate protection.
3. active is long-term, passive is short term protection.
4. memory cells ARE produced in active, not in passive

Question 10

What is a vaccination

Answer 10

vaccine stimulate the production of antibodies and memory cells against the target pathogen without causing illness

Question 11

Why don’t vaccines cause illness

Answer 11

1. they may contain inactivated forms of the pathogen (killed by heat treatment so only useful antigens are intact) e.g. Whooping cough
2. toxin molecules that have been altered and detoxified. e.g. tetanus
3. may contain less virulent form of pathogen (Rubella & polio)
4. may contain isolated antigens from pathogen; e.g. flu
5. GM antigens; e.g. Hepititis B

Question 12

How does a vaccination work

Answer 12

1. pathogens are made safe
2. small amounts of the safe antigen are injected in blood (this is the vaccine)
3. primary immune response is triggered so antibodies and memory cells are produced
4. secondary response is triggered if pathogen reoccurs.

Question 13

What are the disadvantages of vaccines

Answer 13

can take years to produce; with the flu vaccine, scientists have to predict which strain of flu is most likely to be around in next year and produce vaccine for that one; expensive.

Question 14

What are the advantages of vaccines

Answer 14

vaccines give long term immunity to a specific pathogen;
can be used in epidemics and pandemics;
mass vaccinations can be produced;
herd immunity can occur - if a big no. of people are vaccinated, those who aren’t are still protected as a result.

Question 15

What are examples of diseases yet to be treated successfully by a vaccine

Answer 15

HIV and maleria

Question 16

What are medicines

Answer 16

some treat communicable diseases, some non-communicable, some relieve symptoms, some attack the pathogens

Question 17

What are examples of medicines that treat the illness

Answer 17

chemotherapy drugs, antibiotics, antifungals

Question 18

What are sources of medicines

Answer 18

most come from fungi, moulds or plants.

Alexander Flemming is noted with discovering first safe antibiotic (penicillin)

Question 19

Why do forests and other areas of land need to be protected

Answer 19

because they could be potential sources of medicine.
Many medicines use natural compounds found in rainforests, animals, plants, microbes etc.
Some cancer drugs are made using soil bacteria and daffodils are grown to help with treatments for Alzheimer’s.

Question 20

What are examples of widespread medicines

Answer 20

Penecillin - originally sourced from mould growing on melons - an antibiotic against bacertia

Aspirin - sourced from compounds in willow bark - a painkiller and anti-inflammatory

Digoxin - originally extracted from foxgloves - a powerful heart drug used to treat atrial fibrillation and heart failure

Question 21

What are pharmacogenetics

Answer 21

personalised medicine methods- combination of using drugs with an individuals genome and disease information

Question 22

how is pharmacogenetics possible now

Answer 22

because analysing a person’s genome is relatively easy and cheap to do now

Question 23

What’s an example of pharmacogenetics

Answer 23

in approx. all breast cancers, there is a mutation called the HER2 gene; Herceptin and lapatinib shut down the gene activity. Doctors can reduce death from HER2 by 50% by analysing breast tumours and drugs.

Question 24

What is synthetic biology

Answer 24

Using techniques of genetic engineering, we can develop popn.s of bacteria to produce needed drugs that are usually too rare, expensive

Question 25

What’s the antibiotic dilemma

Answer 25

Antibiotics are becoming resistant very quickly which is concerning because they’re very new to treatments. The dilemma is knowing when to prescribe them and when to know they’re not needed.

Question 26

What is selective toxicity

Answer 26

Antibiotics interfere with the metabolism of the bacteria without affecting the metabolism of the human cells.

Question 27

What has caused antibiotics to become resistant

Answer 27

A random mutation may have occurred during bacterial reproduction. This would cause the whole species to be resistant; this would be an advantageous characteristic which would be passed on to daughter cells.

Question 28

What are examples of highly resistant bacteria

Answer 28

methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile
MRSA: bacterium carried on nose/skin of 30 % of popn.;
causes boils, abscesses and septicaemia

C. difficile: bacterium in the gut of 5% of pop.; produces toxins that damage intestines, bleeding, diarrhoea

Question 29

How can antibiotic resistant infections be reduced in the long term

Answer 29

1. minimising use of antibiotics and ensuring people who do need them use them for the whole course to prevent it coming back as a resistant strain
2. good hygiene in hospitals, care homes to stop spread