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How do animals and plants exchange oxygen and carbon dioxide?

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A color-coded periodic table of the elements displays each element's symbol and atomic number, with categories such as alkali metals, noble gases, halogens, transition metals, and actinoid elements distinguished by different background colors. — oxygen group element Modern version of the periodic table of the elements (printable).

The exchange of oxygen and carbon dioxide between plants and animals is a fundamental component of the oxygen cycle. This process relies on the complementary metabolic activities of these organisms.

Respiration and Photosynthesis

Animals and Plants: Both animals and plants use oxygen for cellular respiration, a process that converts food into energy and releases carbon dioxide as a waste product. In humans, this gas exchange occurs in the lungs, where oxygen and carbon dioxide move between the air and blood via diffusion across alveolar membranes.312
Photosynthesis: Terrestrial plants and algae take up the carbon dioxide released by respiration and convert it into carbohydrates through photosynthesis. Oxygen is released as a by-product of this process, replenishing the atmosphere and water.3

This continuous cycle ensures that oxygen remains available for life-sustaining activities, while carbon dioxide is recycled back into organic matter by photosynthetic organisms.3