Adaptive Immunity — Flashcards & Quiz

Q1: What is the role of B lymphocytes (B cells)?

B cells are part of the adaptive immune system (humoral immunity). When activated by an antigen, B cells differentiate into plasma cells that produce antibodies specific to that antigen. Memory B cells persist for rapid response upon re-exposure.

Q2: What is the role of T lymphocytes (T cells)?

T cells are part of cell-mediated immunity. Helper T cells activate B cells and other T cells. Cytotoxic (killer) T cells directly destroy infected cells. Memory T cells remain for future rapid response. T cells recognise antigens presented on MHC molecules.

Q3: What is the difference between active and passive immunity?

Active immunity: body produces its own antibodies and memory cells. Can be natural (infection) or artificial (vaccination). Long-lasting. Passive immunity: body receives pre-made antibodies from another source. Natural (mother's antibodies via placenta/breast milk) or artificial (injection of antibodies). Short-lived.

Q1: B cells produce antibodies as part of the humoral immune response.

Answer: TRUE

B cells differentiate into plasma cells that secrete antibodies specific to antigens. This antibody-mediated response is called humoral immunity.

Q2: Helper T cells directly kill infected cells.

Answer: FALSE

Helper T cells COORDINATE the immune response by activating B cells and cytotoxic T cells. CYTOTOXIC (killer) T cells directly destroy infected cells.

Q3: Passive immunity provides long-lasting protection because it generates memory cells.

Answer: FALSE

Passive immunity provides SHORT-LIVED protection because the body receives pre-made antibodies but does NOT produce its own memory cells. Only active immunity generates memory cells.