For the purposes of ¾

(a) section 6 (1) (a), a person shall, unless the contrary is proved, be deemed to have in his possession a prohibited drug with intent to sell or supply it to another if he has in his possession a quantity of the prohibited drug which is not less than the quantity specified in Schedule V in relation to the prohibited drug; or

(b) section 7 (1) (a), a person shall, unless the contrary is proved, be deemed to have in his possession, or to cultivate, prohibited plants of a particular species or genus with intent to sell or supply those prohibited plants or any prohibited drug obtainable therefrom to another if he has in his possession, or cultivates, a number of those prohibited plants which is not less than the number specified in Schedule VI in relation to that species or genus.