Similarities: Both of these are biogeochemical cycles,meaning that the chemicals spend a portion of the cycle in living things (hence the bio) and a portion in the nonliving environment (geo). They are also similar in that they both recycle nutrients that are essential to all organisms.
The hydrosphere refers to the water on the earth crust. If there were no hydrosphere, we would not have lakes, oceans, rivers, or even a hose full of water.
