4.1.1 Diseases immunity bit

Question 1

active immunity

Answer 1

immune system makes its own antibodies after being stimulated by a pathogen

Question 2

active immunity - natural

Answer 2

when you become immune after catching a disease

Question 3

active immunity - artifical

Answer 3

when you become immune after you’ve been given a vaccination containing a harmless dose of the antigen

Question 4

passive immunity

Answer 4

get given antibodies made by a different organism

immune system doesn’t produce any antibodies of its own

Question 5

passive immunity - natural

Answer 5

when a baby becomes immune due to the antibodies it receives from its mother through placenta and breast milk

Question 6

passive immunity - artifical

Answer 6

become immune after being injected with antibodies from someone else

Question 7

active vs passive

Answer 7

active

• requires exposure to antigen
• takes a while for protection to develop
• protection is long term
• memory cells are produced

passive

• no exposure to antigen
• protection is immediate
• protection is short-term
• memory cells aren’t produced

Question 8

what is an autoimmune disease

Answer 8

when an organism’s immune system isn’t able to recognise self-antigens

the immune system treats the self-antigens as foreign tissues and launches an immune response against the organism’s own tissues

a disease resulting from this abnormal immune response is known as an autoimmune disease

• usually chronic (longterm)
• often can be treated but not cured

Question 9

autoimmune disease - lupus

Answer 9

caused by the immune system attacking cells in the connective tissues

this damages the tissues and causes painful inflammation

can also affect the skin and joints as well as organs - lungs and heart

Question 10

autoimmune disease - rheumatoid arthritis

Answer 10

caused by immune system attacking cells in the joints

causes pain and inflammation

Question 11

vaccines - why are they used

Answer 11

helps control disease and prevent epidemics

- avoid the slower primary immune response

Question 12

vaccines - what

Answer 12

contain antigens - may be free or attached to a dead or attenuated (weakened) pathogen

this causes your body to produce memory cells against a particular pathogen without the pathogen causing disease

so become immune without getting any symptoms

Question 13

vaccines - herd immunity

Answer 13

if most people in a community are vaccinated the disease becomes extremely rare

this means people who haven’t been vaccinated are unlikely to get the disease because there is no one to catch it from

this helps prevent epidemics - mass outbreak of disease

Question 14

vaccination vs immunisation

Answer 14

vaccination - the administration of antigens (in a vaccine) into the body

immunisation - the process by which you develop immunity (doesn’t have to be vaccination but vaccination is immunisation)

Question 15

routine vaccinations - MNR

Answer 15

protects against measles, mumps and rubella

usually given to children as an injection around a year old, and again before they start school

contains attenuated measles, mumps and rubella virus

Question 16

routine vaccinations - meningitis C vaccine

Answer 16

protects against the bacteria that cause Meningitis C

first given as an injection at 3 months old

boosters are given to 1-year-olds and teenagers

Question 17

vaccines/vaccination programs - why do they change?

Answer 17

eg. influenza
the influenza vaccine changes every year because the antigens on the surface of the influenza virus change regularly, forming new strains of the virus
- memory cells produced from vaccination with one strain will not recognise a different strain as the strains are immunologically distinct

every year, different strains circulating in population, so a different vaccination has to be made

• laboratories collect samples of these different strains, and organisations (world health organisation and centre for disease control) test the effectiveness of different influenza vaccines against them
• new vaccines developed and the most effective one against the recent virus is chosen

governments and health authorities then implement a program of vaccination using the most suitable vaccines - sometimes people are given a vaccine that protects then from a strain causing an epidemic in another country - helps stop strain spreading globally

Question 18

what are medical drugs manufactured from

Answer 18

from natural compounds - in plants, animals or microorganisms

Question 19

where does penicillin come from

Answer 19

fungus

Question 20

where do cancer drugs come from

Answer 20

soil bacteria

Question 21

what is used to treat alzheimer’s disease

Answer 21

daffodils

Question 22

why do possible sources of drugs need to be protected

Answer 22

only a small proportion of organisms have been investigates - its possible that plants or microorganisms exist that contain compounds that could be used to treat currently incurable diseases

possible sources of drugs need to be protected by maintaining biodiversity

if we don’t protect then, some species could die out before we get a chance to study them
- even organisms that have already been studied could still prove useful sources if medicines as new techniques are developed for identifying, purifying and testing compounds

Question 23

personalised medicines - why

Answer 23

your genes determine how your body responds to certain drugs

different people respond to the same drug in different ways

this makes certain drugs more effective for some people than others

Question 24

personalised medicines - what

Answer 24

medicines that are tailored to an individual’s DNA

the theory is that if doctors have your genetic information, they can use it to predict how you will respond to different drugs and only prescribe the ones that will be the most effective for you

Question 25

personalised medicines - future

Answer 25

scientists hope that by studying the relationship between someone’s genetic make-up and their responsiveness to drugs, more effective drugs can be produced in the future.

Question 26

synthetic biology - what

Answer 26

involves using technology to design and make things like artificial proteins, cells and even microorganisms

Question 27

synthetic biology - application

Answer 27

application in lots of different areas

medicine
- scientists are looking at engineering bacteria to destroy cancer cells, while healthy body cells intact

Question 28

antibiotics - what?

Answer 28

chemicals that kill or inhibit the growth of bacteria

Question 29

antibiotics - use? why?

Answer 29

used by humans as drugs to treat bacterial infections

because they can usually target bacterial cells without damaging human body cells

Question 30

antibiotics - penicillin

Answer 30

the first antibiotic to be isolated (by Alexander Flemming, in 1928)

Question 31

antibiotics - helpful?

Answer 31

widespread use from the mid-twentieth - partly thanks to the successful treatment of soldiers

been able to deal with bacterial infections pretty easily using antibiotics
- as a result of this the death rate from the infectious bacterial disease has fallen dramatically

Question 32

antibiotics - risks

Answer 32

side effects

severe allergic reactions

antibiotic resistance

Question 33

antibiotic resistance - what?

Answer 33

there is genetic variation in a population of bacteria
- genetic mutations make some bacteria naturally resistant

for the bacterium, this is an advantage - better able to survive even in a host whos being treated with antibiotics to get rid of the infection, and so it lives for longer and reproduces
- this leads to the allele for antibiotic resistance being passed on to lots of offspring (natural selection)

the how antibiotic resistance spreads and becomes more common in a population over time

Question 34

antibiotic resistance - why is it bad?

Answer 34

this is a problem for people who become infected with these bacteria because you can easily get rid of them with antibiotics

increased use of antibiotics means that antibiotic resistance is increasing ‘superbugs’ that are resistant to known antibiotics are becoming more common

this means we are less able to treat some potentially life-threatening bacterial infections

Question 35

antibiotic resistant bacteria - MRSA

Answer 35

meticillin-resistant Staphylococcus aureus

causes several serious wound infections

is resistant to several antibiotics - including meticillin

Question 36

antibiotic resistant bacteria - clostridium difficile

Answer 36

infects the digestive system
- usually causing problems in people who have already been treated with antibiotic

it is thought that the harmless bacteria that are normally present in the digestive system are killed by the antibiotics which C.difficle is resistant to

this allows C.difficile to flourish - C.difficle produces a toxin, which causes severe diarrhoea, fever and cramps

Question 37

antibiotic resistant - how to overcome

Answer 37

developing new antibiotics

modifying existing ones

• this isn’t easy

Question 38

how to reduce likelihood of antibiotic resistance developing

Answer 38

doctors encouraged to reduce their use of antibiotics

• don’t prescribe them for minor infections
• don’t prescribe them to prevent infections (except in patients with weak immune systems, HIV)

patients are advised to take all of the antibiotics they’re prescribed to make sure the infection is fully cleared and all the bacteria have been killed
- which reduces the likelihood of a population of antibiotic-resistant bacteria developing