question_answer 21)

  Biosphere is (a) a component in the ecosystem (b) composed of the plants present in the soil (c) life in the outer space (d) composed of all living organisms present on earth which interact with the physical environment

Answer:

                  (d) Biosphere is composed of all living organisms present on earth which interact with their physical environment. In other words a biosphere or ecosphere term is collectively used for all the ecosystems of world. Ecosphere or biosphere cannot be defind by other three options, as they represent only a part of ecosystem.