An antigen is

  1. a protein made by plasma cells
  2. a type of phagocyte
  3. a hydrolytic enzyme
  4. a molecule that stimulates an immune response
Answer

D) a molecule that stimulates an immune response

Antigens trigger antibody production. AS & A Level Biology · Topic 11 Immunity · 11.1 The immune system

Biology MCQ · More A Level Biology: Immunity MCQs · Practise