A hormone is

  1. an electrical impulse
  2. a type of neurone
  3. an enzyme in the gut
  4. a chemical made by a gland and carried in the blood to target organs
Answer

D) a chemical made by a gland and carried in the blood to target organs

Definition of a hormone. O Level Biology · Topic 14 Coordination and Control · 14.3 Mammalian hormones

Biology MCQ · More O Level Biology: Coordination and Control MCQs · Practise