(a) Name three main parts of the human brain

(b) State the functions of the following:
(i) Cerebrum
(ii) Hypothalamus
(iii) Medulla Oblongata.

(c)(i) List three organs of a higher plant that can respond to stimulus
(ii) What is tactic movement?

(d) Explain the following terms, giving one example in each case:
(I) Phototaxis
(ii) Hydrotaxis
(iii) Chemotaxis.