types of immunity

Question 1

define active immunity

Answer 1

exposure to antigen, triggering specific immune response, antibodies made by individual

Question 2

define passive immunity

Answer 2

no exposure to antigen, pre-made antibodies received by individual

Question 3

define artificial passive immunity

Answer 3

results from administration of antibodies from another animal against a dangerous pathogen

Question 4

define artificial active immunity

Answer 4

results from exposure to a safe form of a pathogen like in vaccination

Question 5

define natural active immunity

Answer 5

results from response of body to invasion of a pathogen

Question 6

define natural passive immunity

Answer 6

given to an infant mammal by the mother through the placenta/breast milk

Question 7

define autoimmune disease

Answer 7

condition/illness resulting from the immune system acting against its own cells and destroying healthy tissue in the body

Question 8

name 3 examples of autoimmune diseases

Answer 8

• Type 1 diabetes
• Rheumatoid Arthritis
• Lupus

Question 9

suggest how autoimmune diseases may occur

Answer 9

occur when the immune system recognises ‘self’ antigens as ‘non self’, triggering immune response against its own cells

Question 10

define vaccine

Answer 10

safe form of an antigen injected into bloodstream to provide artificial active immunity against a pathogen bearing the antigen

Question 11

describe 5 ways in which antigens can be obtained for use in vaccines

Answer 11

• killed/inactivated bacteria and viruses
• weakened strains of live bacteria/viruses
• toxin molecules that have been altered/detoxified
• isolated antigens extracted from the pathogen
• genetically engineered antigens

Question 12

describe how vaccination results in artificial active immunity

Answer 12

• small amount of safe antigen-containing vaccine is injected into blood
• primary immune response triggered by foreign antigens and body produces antiodies + memory cells as if infected by live pathogen
• if in contact with that pathogen, but live, secondary immune response triggered and pathogen destroyed rapidly before suffering symptoms of disease

Question 13

define epidemic

Answer 13

when a communicable disease spreads rapidly to a lot of people at a local/national level

Question 14

define pandemic

Answer 14

same disease spreads rapidly across a number of countries and continents

Question 15

define herd immunity

Answer 15

large part of population of an area is immune to a disease making the chances of an outbreak very low

Question 17

explain how vaccination of a significant number of people in a population can provide protection for unvaccinated people

Answer 17

If enough people vaccinated, herd immunity is reached = less transmission and less likely for disease to reach an unvaccinated person - it cannot spread through a population that is already immune

Question 18

suggest which members of a population are likely to need protection through herd immunity.

Answer 18

• people allergic to vaccine
• people with weakened immune systems that need to take immunosuppressants

Question 19

suggest why the influenza vaccine needs to be redeveloped and people need to be revaccinated each year.

Answer 19

• virus causing flu mutates regularly so antigens on surface change too
• vaccines must be redeveloped as people will no longer be able to form secondary response against the mutated variant

Question 20

explain the need to maintain biodiversity in relation to discovery of new medicines.

Answer 20

ensure we do not destroy an organism which could be key to a life-saving drug

Question 21

define personalised medicine

Answer 21

combination of drugs that work with your individual combination of genes and disease

Question 22

give an example of how treatment is being personalised

Answer 22

30% of breast cancer patients have mutation on a certain gene
- activity of that gene can be shut down by a drug

Question 23

suggest the value of personalising medicine to a persons genetic information

Answer 23

improve how diseases are treated by working out the best approach for a specific person

Question 24

define synthetic biology

Answer 24

design and construction of new biological parts, devices and systems and re-designing existing natural biological systems for useful purposes

Question 25

give 3 examples of how synthetic biology may lead to better medical treatments

Answer 25

• develop bacteria using genetic engineering that can produce drugs that are rare/expensive
• genetically modify mammals to produce therapeutic proteins in milk
• nanotechnology to deliver drugs to specific sites in cells

Question 26

define antibiotic

Answer 26

chemical that kills or inhibits bacterial growth

Question 27

define selective toxicity

Answer 27

ability to interfere with the metabolism of a pathogen without affecting the cells of the host

Question 28

suggest ways in which antibiotics may act selectively on bacterial cells but not human cells.

Answer 28

• destroy/affect peptidoglycan production - humans dont need it + it is what the bacterial cell wall is made of
• target their metabolic pathways and not human ones

Question 29

explain why antibiotics do not work on viral infections

Answer 29

• specifically target bacterial machinery
• viral infections have completely different structure and are non-living
• viral infections do not have cell wall that can be attacked - protein coat instead

Question 30

outline different ways 4 common antibiotics have their effect

Answer 30

• penlillin and cephalosporins weaken cell wall so bacterium more easily damaged by immune reaction
• sulfonamides interfere with metabolic reactions
• tetracyclines and streptomycin inhibit protein synthesis
• polymixines make holes in cell surface membrane altering its activity

Question 31

suggest two ways in which the use of antibiotics may be increasing the likelihood of resistance evolving.

Answer 31

• over-prescribing antibiotics
• giving farm animals antibiotics to prevent them from getting infected and reducing business profits

Question 32

suggest two methods to reduce the likelihood of resistance developing in bacteria.

Answer 32

• minimise antibiotic use
• good hygiene - impact spread of infections