Life is a biological entity that is indigenous to a biological system that can reproduce, transform energy, grow and regulate itself in a sustainable environment as found on Earth. The common characteristic traits of a system with life are homeostasis, metabolism and reproduction. A life can be of a single living system like a cell, or a group of living system making a sophisticated biological living system like Homo sapiens.
Frequently Asked Questions
Why life exists only on Earth?
In our solar system, Earth is supposed to be the only habitable zone that can sustain life at the time of this writing. When the whole universe is considered, there may be similar planetary systems like the Solar system with habitable planets that can sustain life. However, Earth is the only planet we have observed organic life on.
Why life is carbon based?
Carbon is one of the abundant elements along with Hydrogen, Helium, Nitrogen, and Oxygen. Carbon has four valence electrons, making it as the versatile element to bond with four new elements and form stable and complex molecules and macromolecules that are essential for life.