(d) : Predator and prey evolve together. The prey is part of the predator's environment, and the predator dies if it does to get food, so it evolves whatever is necessary in order to eat the prey. Likewise, the predator is part of the prey's environment, and the prey dies if it is eaten by the predator, so it evolves whatever is necessary to avoid being eaten. So, predators cannot lead to the extinction of prey species. Nicotine is an alkaloid found in the night shade family of plants (Solanaceae) that constitutes approximately 0.6−3.0% of dry weight of tobacco, with biosynthesis taking place in the roots and accumulation occurring in the leaves. Strychnine is an alkaloid plant toxin extracted chiefly from Nux vomica; formerly used as a stimulant. These are not metabolic disorder products but are metabolic wastes.