7.-(2) Subject to sub-section (3), the following shall not be regarded as invention within the meaning of sub-section (1), namely:-
(a) a discovery, scientific theory or mathematical method;
(e) substances that exist in nature or if isolated therefrom
(4) A patent shall not be granted
(b) for plants and animals other than micro-organisms, and essentially biological processes for the production of plants or animals other than non-biological and microbiological processes;