immunity

Question 1

pathogens

Answer 1

A disease-causing organism.

Question 2

What is a transmissible disease

Answer 2

A disease in which the pathogen can be passed from one host to another.

Question 3

Mechanical barriers:

Answer 3

oNostrils contain hairs that help trap dust
oSkin has a thick outer layer of dead cells
Chemical barriers:
oSticky mucus which can trap pathogens
oIn the stomach, hydrochloric acid is secreted which kills
many of the bacteria in food

Question 4

Cells:

Answer 4

Pathogens that manage to get through all these defences are usually destroyed by
white blood cells:

oSome of these cells take in and digest the pathogens by phagocytosis
oOthers produce antibodies that incapacitate or kill the pathogen
oVaccination against disease helps antibodies to produce very quickly

Question 5

What is an antigen? Where are they found?

Answer 5

A protein that is present on the membrane of every living cell that indicates to the body, Antigens are proteins that are found on the surface of the pathogen

Question 6

active immunity

Answer 6

immunity you develop after being exposed to an infection of from a vaccine - natural an artificial

Question 7

passive immunity

Answer 7

immunity you aquire from someone or somtn else - natural- antibodies transmitted from mother to baby
artifivial - antibodies aquired from an immune serum medicine

Question 8

How do vaccines prevent the spread of disease?

Answer 8

immunise children against diseases caused by pathogens

Question 9

Explain the process of vaccination

Answer 9

oHarmless pathogen given which has antigens
oAntigens trigger an immune response by lymphocytes which produce antibodies
oMemory cells are produced that give long-term immunity