Answer:At heart, all life on Earth uses a membrane that separates the organism from its environment. ... In this regard, water is essential simply because it's a liquid at Earth-like temperatures. Because it flows, water provides an efficient way to transfer substances from a cell to the cell's environment.
The Cell Theory, credited to Theodor Schwann and Matthias Jakob Schleiden, was founded in the 1830s and states that the basic unit of life is the cell, cells come from preexisting cells, and all living organisms are composed of one or more cells.
