I believe it is the very first one
hope it helps :)
No, the biosphere does not exhibit a clear boundary as life always comes to an end.
The biosphere comprises all the living things of the world, like all the plants and animals. It is considered as the global ecosystem, that is, the gathering of all the planet's ecosystems. It comprises the land and the atmosphere. It is usually considered as the zone of life, where all the species of the planet thrives.
Because Air itself is not an element. it is made up by different elements such as Oxygen and nitrogen. since its made up of a mix of different elements, its rather a homogeneous mixture :)
A.glucose is a product of the photosynthesis reaction carbon dioxide is a reactant.
