Identify the presented antigen and activated lymphocyte, follow clonal expansion into the correct effector cells and link their action to pathogen removal or memory.
There are four types of immunity.
Natural active immunity can develop when a person is infected with a virus.
Explain why both T helper cells and T killer cells are needed in the immune response to a virus.
An explanation that includes four of the following points:
- T helper cells \{activate / stimulate\} B cells (to divide) (1)
- because antibody will be needed for opsonisation (1)
- T helper cells \{activate / stimulate\} T killer cells (to divide) (1)
- because T killer cells destroy (virus-infected) cells (1)
- so that virus can be \{engulfed / destroyed\} by macrophages (1)
ACCEPT stimulate humoral response
ACCEPT antibodies prevent viruses binding to host cells ACCEPT stimulate cell-mediated response
ACCEPT a description
DO NOT ACCEPT killed pathogen in context of bacteria
(4)