Final answer:
Photosynthesis and cellular respiration cycle carbon through the environment by exchanging carbon dioxide and oxygen. Plants absorb carbon dioxide during photosynthesis to produce glucose, and animals return carbon dioxide to the atmosphere through cellular respiration.
Step-by-step explanation:
Photosynthesis and cellular respiration cycle the element carbon through the environment. When a plant performs photosynthesis, it absorbs carbon dioxide from the air and produces glucose (sugars) that serves as a food source for plants and the foundation for the food web. In contrast, when animals engage in cellular respiration, they utilize the oxygen formed during photosynthesis to metabolize glucose and, as a result, exhale carbon dioxide, replenishing the atmosphere for further photosynthesis by plants.
Cellular respiration and photosynthesis are both pivotal components of the carbon cycle, which is a vital pathway through which carbon is recycled within the biosphere. This exchange plays a crucial role in maintaining stable levels of both carbon dioxide and oxygen in the atmosphere.
Organisms, from bacteria to humans, rely on the breakdown of carbohydrates, like glucose, to access energy. This involves a cyclical process where carbon dioxide is both a byproduct from cellular respiration and a substrate necessary for photosynthesis. Plants are unique as they can perform both photosynthesis and cellular respiration, although the latter occurs in all living organisms to perform important life functions.