The part of the environment where life exists?

• A. Open System
• B. Lithosphere
• C. Biosphere
• D. Closed System

Answer: (C)

Life exists in the biosphere, the global zone that includes all ecosystems where living organisms interact with air, water, soil, and rocks. It covers every place that can support life—from deep oceans and soil to surface land and even the lower atmosphere—because life depends on the resources and processes provided by these environments. The lithosphere, hydrosphere, and atmosphere are the physical layers of Earth, and while life depends on them, they aren’t the part that specifically denotes where living organisms exist—that distinction is the biosphere. The terms open system and closed system describe how energy or matter flows in or out, not where life is found, so they don’t define the realm that supports living organisms.