Immune Response

Question 1

Phagocytosis

Answer 1

Phagocyte attracted to pathogen by chemicals or foreign antigen
Engulfs pathogen
Bacteria in phagosome
Fuses with lysosome
Form phagolysosome Pathogen hydrolysed;

Question 2

Hum oral response

Answer 2

Pathogen with foreign antigen detected
Engulfed by phagocyte
Antigen attached to cell membrane of phagocyte (antigen presentation)
Th cell with complementary receptor binds to antigen
Th cell stimulates B cell
Specific B cell activated
Divides to form clone (clonal selection)
By mitosis
Plasma cells produced
Release antibodies
Antibody specific to antigen
Antibody destroys cells with antigen

Question 3

Cell mediated response

Answer 3

Pathogen with foreign antigen detected
Engulfed by phagocyte
Antigen attached to cell membrane of phagocyte (antigen presentation)
Th cell with complementary receptor binds to antigen
Activate T cell to divide
By mitosis
T cells specialize to form
• Memory cells
• Stimulate phagocytes to engulf pathogens
• Stimulate B cells to secrete antibodies.
• Activate cytotoxic T cells
Cytotoxic T cells kills infected body cells By producing porforin
Makes hoes in cell membranes.