Answer: IgE.
- A IgG
- B IgE
- C IgA
- D IgM
Correct answer: B. IgE
Explanation: IgE binds mast cells and basophils and triggers the histamine release of allergic (hypersensitivity) reactions.
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.