The hydrologic cycle moves water through the biosphere. Water makes up over 1/2 of a typical mammal's body weight, and no organism can survive without it. Water allows essential molecules to move within and between cells, draws nutrients into the leaves of trees, dissolves and removes toxic meaterials, and performs critical functions. IT IS A BIOGEOCHEMICAL CYCLE. BIOGEOCHEMICAL  Cycles- The movement of matter within and between ecosystems involves the cycles of biological, geological, and chemical processes.

Processes: Tanspiration- The realease of water from leaves during photosynthesis.

Evapotranspiration- The combined amount of evaporation and transpiration. Evaporation- Water enters the atmosphere to be redistributed.

Precipitation- Water returns to the Earth as rain, snow, etc.

Infiltration- Precipitation percolates through the soil. Percolation- Water enters the soil.

Condensation- Water forms clouds in the atmoshpere.