Four of these are true of the carbon cycle. Large inorganic supply is tied up in fossil fuels. Part of its cycle is spent tied up with hydrogen. It is found in the shell of mollusks. In one form, it may affect the acidity of aquatic ecosystems.
Bacteria play a major, multi-step role in the cycle.
Four of these correctly pair a biome with its characteristic. Four of these are true of freshwater ecosystems. Catfish feed on the bottom of a lake, while sunfish swim in shallow waters. This description of community structure is a. diurnal. A mammal feeds at night, nests in the spring, and has few predators.