Anything that contains or supports life is part of the biosphere.

Core idea

  • The biosphere is the global “zone of life” on Earth, including all living organisms and the thin layer of land, water, and air where they exist.
  • It includes parts of the lithosphere (upper soil and rocks with life), hydrosphere (water with life), and lower atmosphere (air where organisms live).

So which things are part of the biosphere?

Examples that are part of the biosphere:

  • Plants, animals, fungi, and microorganisms (all living things).
  • Soil that contains organisms, tree-covered land, coral reefs, lakes, rivers, and oceans with life.
  • The portion of the atmosphere where birds, insects, and microbes live.

Examples that are not part of the biosphere:

  • Earth’s deep mantle and core, where life does not occur.
  • Completely lifeless regions with no organisms and no interaction with living systems.

Typical multiple‑choice framing

In many textbook or exam questions, when asked “Which of the following is part of the biosphere?” the correct option is often something like:

  • “All regions of air, water, and land where life exists”
  • Or “Lithosphere, hydrosphere, and atmosphere (where life is present).”

Information gathered from public educational resources and science references available on the internet and portrayed here.