What is the region of Earth's crust and atmosphere occupied by living organisms called?

This region is called the biosphere. The biosphere encompasses all areas of Earth where life exists, extending from the deepest ocean trenches (approximately 11 kilometers below sea level) to the upper atmosphere (roughly 10 kilometers above ground level). It includes portions of the lithosphere (Earth's crust and upper mantle), the hydrosphere (all water bodies), and the atmosphere (the air surrounding Earth). The biosphere is a relatively thin zone compared to Earth's total size, yet it contains incredible biodiversity and complex interactions among living organisms and their physical environment. Understanding the biosphere is crucial for conservation efforts and managing human impacts on Earth's life-support systems.