The significance of the carbon-oxygen cycle lies in its role in maintaining the balance of essential elements in Earth's ecosystems. This cycle involves the exchange of carbon dioxide and oxygen between plants, animals, and the atmosphere. During photosynthesis, plants absorb carbon dioxide and release oxygen, while animals consume oxygen and release carbon dioxide through respiration. This interplay is vital for sustaining life, regulating atmospheric composition, and mitigating climate change, thus ensuring ecosystem stability and health.