Explore how antigen presentation activates T- and B-lymphocytes, drives clonal expansion and produces antibodies and memory cells in IB Biology HL C3.2.6.
Multicellular organisms benefit from cell specialization and division of labour.
Explain how cells in the bloodstream cause a specific immune response.
(specific immune response is) production of antibodies in response to a particular pathogen;
antibody is specific to/binds to a specific antigen;
macrophages/phagocytes engulf/present antigens from pathogens/viruses/bacteria;
T lymphocytes activated by antigens/antigen presentation/antigens presented by macrophage;
(activated) T lymphocytes activate B lymphocytes;
only B lymphocytes that produce antibodies against the antigen/pathogen are activated;
(activated) B lymphocytes clone/divide by mitosis to form plasma cells;
plasma cells then secrete (large quantity) of an antibody/secrete antibodies of same type;
some B lymphocytes/plasma cells form memory cells;
memory cells give long lasting immunity/faster response to a disease/pathogen;