Answer: Cell-mediated immunity.
- A The innate skin barrier
- B Antibodies present in tears
- C Cell-mediated immunity
- D Passively acquired immunity
Correct answer: C. Cell-mediated immunity
Explanation: Graft rejection is chiefly a cell-mediated response - T cells recognise the foreign MHC on the transplanted tissue.
An antibody is Y-shaped, with two identical antigen-binding sites at the tips of the variable regions - each shaped to recognise one specific antigen - while the constant (Fc) region at the base is recognised by immune cells to trigger further responses.
Concept context
Innate and adaptive immunity, B cells, T cells, antibodies, vaccines, and immune disorders. Critical for NEET.