Bioaccumulation is the increase in concentration of poisons in the tissues of animals high on the food chain. Mineral cycles include an environmental reservoir of low-energy molecules which are the waste product of catabolism and the raw materials of metabolic synthesis. Mineral cycles may be generalized. The inorganic substances may be lost from the ecosystem into a SINK, where they are unavailable to organisms. The flow of energy drives the cycling of nutrients.
Organisms use oxidation-reduction reactions to gain and transfer energy.
Terrestrial biomes are defined by the dominant plant type. Biomes are products of climates, soil types, chance, and history. Biomes may intergrade or have sharp boundaries. This implies that the energy and materials in living systems must come from the non-living environment. This implies that every transformation of energy is accompanied by a loss of usable energy.