Bioscience:Biosphere Cycles
On our earth, there is only very thin zone where living things can flourish. The habitable zone operates as a closed system and contains only a fanlight amount of metaphor life. Except for sunlight, nothing comes in or out. Everything within the biosphere is used and reused over and over again. Plants become food for animals. Animals in turn become the food for other animals. At each step, items are consumed and digested.
- Added:2006
- Country:Australia
- Duration:25
- Time of update:2011/3/11 15:03:55