Biology Regents Practice Exam 2026 – The All-in-One Guide to Master Your Regents!

The main purpose of the carbon cycle in ecosystems is to maintain atmospheric levels of carbon dioxide. This biogeochemical cycle involves the movement of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms.

Carbon dioxide is crucial for photosynthesis, a process by which plants, algae, and some bacteria convert carbon dioxide and sunlight into energy in the form of glucose, releasing oxygen as a byproduct. By cycling carbon, ecosystems ensure that the levels of carbon dioxide in the atmosphere remain balanced, which is vital for climate stability and supporting life. If carbon levels were too high or too low, it would disrupt the delicate balance required for various forms of life to thrive.

While improving soil fertility, providing energy for organisms, and facilitating plant growth are important functions in their own right, they are not the main purpose of the carbon cycle. Instead, these functions are consequences of a well-maintained carbon cycle that sustains the overall health of ecosystems.