The Earth's Biosphere

Multiple Choice

The Earth's biosphere

A) consists of only terrestrial organisms, while the hydrosphere includes aquatic and marine organisms.
B) only includes the biotic components of an ecosystem, with the abiotic components being considered part of the lithosphere, hydrosphere, or atmosphere, respectively.
C) is more a theoretical construct than an observable sphere of study.
D) extends from the ocean floor to an altitude of approximately 8 km (5 mi) into the atmosphere.