Which layer of the Earth is essential for sustaining life due to its gas composition?

• A. Lithosphere
• B. Atmosphere
• C. Hydrosphere
• D. Biosphere

Answer: (B)

The atmosphere is the layer of the Earth that is crucial for sustaining life primarily because of its composition of gases, notably oxygen and carbon dioxide. These gases are essential for respiration in most living organisms and play a vital role in photosynthesis, which is conducted by plants to produce food and oxygen.

The atmosphere also protects living beings from harmful solar radiation and helps regulate the Earth’s temperature, creating a stable environment suitable for life. Additionally, it contains water vapor, which is necessary for weather patterns and provides precipitation, further supporting ecosystems.

While other layers, like the lithosphere (land), hydrosphere (water), and biosphere (the zone of life), are important for different aspects of life on Earth, they heavily depend on the gaseous envelope provided by the atmosphere to sustain life processes.