Final answer:
Photosynthesis is the process that cycles carbon from the atmosphere into living organisms by converting carbon dioxide into organic compounds like glucose, which can then enter the food chain.
Step-by-step explanation:
The mechanism that helps carbon to cycle from the atmosphere to living organisms is photosynthesis. This important biological process is carried out by plants, algae, and some bacteria. During photosynthesis, these organisms take in carbon dioxide (CO2) from the atmosphere and use it, along with water, to produce glucose and release oxygen. Thus, photosynthesis converts atmospheric CO2 into carbohydrates, which are then available for consumption by animals and other organisms, leading to the transfer of carbon through the ecosystem.
Photosynthesis is critical for supporting life on Earth because it forms the base of the food chain. It provides the organic compounds needed by consumers (animals and other non-photosynthetic organisms) and contributes to oxygen generation. Furthermore, while cellular respiration cycles the organic carbon back into CO2 gas, primarily photosynthesis brings atmospheric CO2 into the biological carbon cycle, thus helping to regulate the amount of CO2 in the atmosphere and mitigate the greenhouse effect to some extent.