Answer: Acquired immunity.
- A Innate immunity
- B Acquired immunity
- C A physical barrier
- D An inflammatory reflex
Correct answer: B. Acquired immunity
Explanation: Acquired (adaptive) immunity is specific to a particular pathogen and improves after exposure, with memory.
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.