immunity

Question 1

What are the two types of immunity ?

Answer 1

• Active immunity
• Passive immunity

Question 2

What is active immunity ?

Answer 2

Active immunity is acquired when exposed to pathogens/ antigens triggering a specific immune response and causing antibodies to be produced

Question 3

What is natural active and artificial active immunity ?

Answer 3

• Naturally acquired through exposure to microbes/ pathogens
• Artificially acquired through INJECTED vaccinations contains antigens/ weakened pathogen

Question 4

What are features of active immunity ?

Answer 4

• Involves exposure to pathogen/ antigen
• The body produces memory cells and plasma cells
• Antibodies are produced
• Long-term immunity is acquired

Question 5

What is passive immunity ?

Answer 5

Passive immunity is acquired without an immune response. Antibodies are introduced into the body and no memory cells/ antibodies are produced.

Question 6

What is natural and artificial passive immunity ?

Answer 6

• Artificial passive immunity occurs when people are given an INJECTION / transfusion of the antibodies
• Natural passive immunity occurs when Foetuses receive antibodies across the placenta from their mothers OR Babies receive the initial breast milk from mothers (the colostrum)

Question 7

What are features of passive immunity ?

Answer 7

• No exposure to pathogens/ antigens
• No memory cells or plasma cells are produced
• Antibodies are not produced
• No long-term immunity, another transfusion of antibodies require

Question 8

Compare active and passive immunity ?

Answer 8

Question 9

Define ‘autoimmune disease’ ?

Answer 9

Autoimmune disease : A condition where the immune system attacks itself/ the bodies healthy cells that is recognise as non-self

Question 10

What is an example of autoimmune disease ?

Answer 10

• Rheumatoid arthritis
• Immune system attacks cartilage in joints causing inflammation and pain
• No cure. Steroids/ immunosuppressants can relieve symptoms

Question 11

What are the causes of autoimmune disease ?

Answer 11

• Genetics : Passed down through genes/ alleles
• Environment

Question 12

Define ‘vaccine’ ?

Answer 12

Vaccine : A vaccine is a suspension of antigens that are intentionally put into the body to induce artificial active immunity

Question 13

What are the two types of vaccines ?

Answer 13

• Live attenuated
• Dead/ weakened form of pathogen

Question 14

What do vaccines do ?

Answer 14

• Vaccinations trigger immune response causing memory cells, plasma cells and antibodies to be produced
• Memory cells remain in the blood and allow for rapid secondary response

Question 15

Why may vaccines be ineffective ?

Answer 15

• Pathogens mutate resulting in pathogens have differently shaped antigens on their surface
• This means booster vaccines are required

Question 16

What is antigenic variation ?

Answer 16

The variation in the antigens of pathogens which causes the vaccines to not trigger an immune response

Question 17

What is a epidemic ?

Answer 17

When a disease spreads rapidly on a national level

Question 18

What is a pandemic ?

Answer 18

When a disease spreads rapidly on a global level

Question 19

What is herd immunity ?

Answer 19

• When a sufficiently large proportion of the population has been vaccinated
• This prevents spread of pathogen
• This allows vulnerable individuals unable o have vaccine to be protected/ not encounter pathogen

Question 20

Explain why maintaining biodiversity is important ?

Answer 20

• Bacteria and fungi have provided many antibiotics
• Plants have been major source of drugs/ medicines
• Maintain biodiversity increases chance of finding new drugs
• Once species is extinct, genetics/ potential medicines are lost forever

Question 21

Name examples of sources of medicine from biodiversity ?

Answer 21

• Antibiotics such as penicillin and vancomycin
• Aspirin from will bark
• Digitoxin from foxglove
• Quinine/ antimalarial drug from cinchona tree

Question 22

What is personalised medicine ?

Answer 22

• Choosing Medicine/ drugs based on a persona genome/ genes
• Treatment created for specific patient matched to bacterial infection they have

Question 23

How can synthetic biology be used for new medicines ?

Answer 23

• Genetic modification of organisms ( eg. insulin producing bacteria )
• Producing drugs/ vaccines

Question 24

Define ‘antibiotic’ ?

Answer 24

Antibiotic - Antibiotics are chemical substances that inhibit or kill bacterial cells with little or no harm to human tissue/ cells

Question 25

Explain the process by which antibiotic resistance develops ?

Answer 25

- ANTIOBIOTIC ACTS AS SELECTION PRESSURE - Mutations occur causing a change in the DNA base sequence/ result in bacteria with advantageous alleles - Bacteria conning advantageous alleles are more likely to survive, reproduce and pass advantageous allies to their offspring - Those without alleles are less likely to die and reproduce - Over several generations, the entire population of bacteria may be antibiotic-resistant

Question 26

Explain how antibiotic resistance develops ?

Answer 26

- Overuse of antibiotics and antibiotics being prescribed when not necessary - Large scale use of antibiotics in farming to prevent disease when livestock are kept in close quarters, even when animals are not sick - Patients failing to complete the full course of antibiotics prescribed by doctors

Question 27

How can antibiotic resistance be prevented/ minimised ?

Answer 27

- Doctors avoiding the overuse of antibiotics, prescribing them only when needed - Antibiotics not being used in non-serious infections - When prescribed a course of antibiotics, the patient finishing the entire course - Antibiotics not being used for viral infections

Question 28

How can the spread of already-resiaznt strains be limited ?

Answer 28

- Ensuring good hygiene practices such as handwashing and the use of hand sanitisers - Isolating infected patients to prevent the spread of resistant strains