Explain the life cycle of Water?

The water cycle, or hydrologic cycle, is one of the most important processes to living organisms on Earth. Consider the following facts:

1. Water makes up between 50% and 90% of living things.
2. Water is used as a cooling mechanism (in the form of perspiration) by living organisms.
3. Water is able to absorb and retain heat, producing stable temperatures important to life.
4. Water is the medium in which all chemical reactions occur in cells.
5. Water molecules play central roles in the chemical reactions of life as reactants and/or products.
6. Water is the "universal solvent" that makes minerals available to living organisms.
7. Water transports gases, minerals, and nutrients within living organisms.
8. Water transports minerals and nutrients geographically, and also plays a role in controlling climate.
9. Water is the medium in which much of life exists - streams, rivers, ponds, lakes, and oceans.

These are some of the major ways in which water plays a central role in life. Living organisms cannot go without water for very long. For most humans, this period is somewhere around 2 or 3 days at the most. Is it any wonder why we must avoid polluting and wasting water?

The water cycle depicts the major processes involved in the exchange of water between the atmosphere and the Earth's largest reservoirs - the oceans, the lakes and rivers, and the groundwater.

Water that has evaporated into the atmosphere condenses and falls as precipitation - either rain, snow, sleet, hail, or fog that condenses on colder surfaces. This precipitation will either run off as surface water and collect as streams or rivers, which then flow and feed into ponds or lakes, or it can seep into the ground and collect in huge underground rock formations called aquifers, that act much like sponges.

Gravity eventually causes the water to flow from lakes or streams down into the oceans, where it can reside for long periods of time, or get evaporated back up into the atmosphere as water vapor, which collects as clouds.

Water that gets absorbed into the ground can be taken up by plants, which use the water to transport minerals internally as well as to take part in the photosynthetic process. This water that helps to make up the plant mass can also get transferred to animals that feed on plants; from there, water can cycle within the food web of an ecosystem, all the way down to the decomposers. At any point in the process, water can be given off to the atmosphere by plant leaves through transpiration, or by animals through respiration, perspiration, or excretion.