The specific immune responseEdexcel A-Level Biology A: Mind map

Exam questions on The specific immune response

1. Antibodies are Y-shaped proteins made by plasma cells. Each antibody molecule is made of four polypeptide chains and has two identical antigen-binding sites. An antibody made against an influenza virus protein was tested and found to bind only to that influenza protein.
   Explain why this antibody does not bind to a protein on the surface of a measles virus.2 marks
2. A patient is infected with a virus. Macrophages in the tissues engulf viral particles, and some days later killer T cells are found destroying virus-infected body cells.
   Describe the role of helper T cells in the immune response to this virus.2 marks
3. Patient P has a rare inherited condition in which no B cells develop, although T cells are normal. Patient Q has a different condition in which helper T cells are absent, although B cells are normal. Both patients suffer repeated infections.
   Describe how a B cell is activated and produces antibodies against an antigen.3 marks