AQA A level Bio 2.4 Immune system Part II

When a vaccine is given to a person, it leads to the production of antibodies against a disease-causing organism. Describe how. (5)

Vaccine contains antigen from pathogen (1)

Macrophage presents antigen on its surface (1)

T cell with complementary receptor protein binds to antigen (1)

T cell stimulates B cell (1)

B cell divides to form clone all secreting / producing same antibody. (1)

What is vaccination? (2)

Injection of antigens (1)

stimulates formation of memory cells (1)

Describe how antibodies are produced in the body following a viral infection. (6)

Virus contains antigen (1)

Virus engulfed by phagocyte/ macrophage (1)

Presents antigen to B cell (1)

Memory cells/ B-cell becomes activated (1)

(divides to) form clones (1)

plasma cells produce antibodies (1)

which are specific to antigen (1)

Explain one advantage of using antibodies from plants to treat a disease, rather than antibodies produced in an experimental animal (1)

fewer ethical difficulties/ less risk of infection (1)

Vaccines protect people against disease. Explain how. (5)

Vaccines contain antigens (1)

memory cells made (1)

on second exposure memory cells produce antibodies (1)

rapidly (1)

antibodies destroy pathogens (1)