Water is essential for all forms of life, it constitutes `65-70%` of the body weight of animals and plants. As compared to other liquids, water has high thermal conductivity, specific heat, dielectric constant, surface tension etc. These properties allow water to play a key role in bioshphere. Due to high dielectric constant, it acts as a good solvent and helps in transportation of minerals and other nutrients for plant and animal metabolism. Water is also required for photosyntheses in plants which releases `O_(2)` into the atmosphere.
