((a) What are hormones? [3 marks]
(b) In a tabular form, state four differences between nervous coordination and hormonal coordination in humans. [4 marks]
(c) State three effects each of:
(i) Over-secretion;
(ii) Under-secretion of thyroxin on mammals. [6 marks]
(d) Make a diagram 10 – 12 cm long of the reflex arc and label fully. [7 marks]