All the available places on earth which support life constitute the

The answer is biosphere. The biosphere refers to all the places on earth where living organisms can exist, which includes the atmosphere, lithosphere (the solid outermost shell of the earth), and hydrosphere (the total amount of water on earth). It is the zone of air, land, and water at the surface of the earth where living organisms are found. The biosphere is the sum of all the ecosystems and includes all the living organisms in the world, their interactions with each other, and with the non-living elements of the environment.