In what way do all living organisms exchange gases?

All living organisms exchange gases through the process of diffusion, which is a fundamental biological principle. Diffusion involves the movement of molecules from an area of higher concentration to an area of lower concentration. In the context of gas exchange, this means that oxygen from the surrounding environment will move into cells where the concentration is lower, while carbon dioxide produced by cellular respiration will move out of the cells into the surrounding environment where its concentration is lower.

This mechanism is universal among living organisms, from simple single-celled organisms like bacteria to complex multicellular organisms like humans. While some organisms utilize specialized organs for gas exchange, such as lungs in mammals or gills in fish, the underlying process of gas exchange is still diffusion. Even plants, which perform photosynthesis, rely on diffusion to take in carbon dioxide and release oxygen. Thus, diffusion is the key process that facilitates gas exchange across various life forms.