Cells And The Immune System

Question 1

Antigens

Answer 1

Molecules (usually proteins) that can generate an immune response when detected by the body

Question 2

Where antigens found

Answer 2

On surface of cells

Question 3

Antigens used for

Answer 3

Used by immune system to identify pathogens, abnormal body cells, toxins, and cells from other individuals of the same species

Question 4

4 main stages of immune response

Answer 4

1. Phagocytes engulf pathogens
2. Phagocytes activate T-cells
3. T-cells activate B-cells, which divide into plasma cells
4. Plasma cells make more antibodies to a specific antigen

Question 5

Phagocytes

Answer 5

White blood cell that carries phagocytosis

Found in boood and tissues

Question 6

Phagocytosis

Answer 6

Engulfment of payjoges

Question 7

Phagocytosis steps

Answer 7

1. Phagocytes recognises the foreign antigens on a pathogen
2. The cytoplasm of the phagocytes moves round the pathogen, engulfing it
3. The pathogen is now contained in a phagocytise vacuole, in the cytoplasm of the phagocyte
4. A lysosome fuses with phagocytise vacuole - the lysozymes break down the pathogen
   5, phagocyte then presents the pathogens antigens - sticks antigens on its surface to activate other immune system cells

Question 8

1st stage of immune response

Answer 8

Phagocytosis

Question 9

2nd stage of immune response

Answer 9

Phagocytes activate T-cells

T cells have receptor proteins on its surface that bind to complementary antigens presented to it by phagocytes
Activates the T-cell
Diff T cells respond in diff ways

Question 10

T-cells

Answer 10

White blood cell

Has receptor proteins on its surface that bind to complementary antigens presented to it by antigens

Question 11

How do Helper T-cells respond to being activated

Answer 11

Release chemical signals that activate and stimulate phagocytes

Question 12

Cytoxic T-cells

Answer 12

Kill abnormal and foreign cells

Question 13

B-cells

Answer 13

Secrete antibodies