The Immune System

Question 1

What is phagacytosis?

Answer 1

•a white blood cell finds a pathogen and engulfs it by changing it’s shape
•the white blood cell ingests and digests the pathogen destroying it

Question 2

What are antibodies?

Answer 2

• White blood cells produce antibodies in response to antigens on the surface of a pathogen
•antibodies have a complementary shape to specific antigens and bind on to them
•This causes the pathogens to cluster together allowing white blood cells to engulf them

Question 3

What are anti toxins?

Answer 3

•some bacteria can produce toxins that damage cells and tissues
•white blood cells respond by producing specific antitoxins that neutralise the toxins secreted by bacteria so there is less cell damage
•this prevents them from causing harm so we don’t feel as ill

Question 4

What are memory cells?

Answer 4

• When the body first comes in contact with a white blood cell it can take a while to produce the right shaped antibodies to attach to the specific antigen
•once the pathogen has been defeated the number of antibodies reduce, but they leave behind ‘memory cells’ to recognise the pathogen if it gets into the blood stream again
• This secondary response is immediate and the person will not show any symptoms. They become immune to the disease