Final answer:
Organisms rely on the atmosphere for carbon dioxide, oxygen, stable temperatures, and indirectly for sunlight, which although not a component of the atmosphere, is vital for photosynthesis.
Step-by-step explanation:
Earth's organisms rely on the atmosphere for a variety of essential functions, including the absorption of carbon dioxide and the production of oxygen through the process of photosynthesis. Oxygen is crucial for cellular respiration in aerobic organisms and is also involved in forming the protective ozone layer that shields Earth from harmful UV radiation. Additionally, the atmosphere helps maintain stable temperatures on Earth through the greenhouse effect, which is modulated by the presence of carbon dioxide and other gases. Sunlight, while not a component of the atmosphere, is critical for photosynthesis, the process that sustains plant life and indirectly, all other life forms on Earth.