Gas exchange involves which two main processes?

Gas exchange involves which two main processes?

• A. Oxygen intake and carbon dioxide expulsion
• B. Oxygen and nitrogen exchange
• C. Carbon dioxide storage
• D. Nitrogen fixation

Answer: (A)

Gas exchange centers on taking in oxygen for cellular use and getting rid of carbon dioxide produced by metabolism. In the lungs, oxygen moves from the air in the alveoli into the blood, while carbon dioxide moves from the blood into the alveoli to be exhaled. This exchange happens by diffusion across the respiratory membrane, driven by differences in partial pressures of the gases. So the two main processes are oxygen intake and carbon dioxide expulsion. The other options don’t fit because nitrogen is not a key gas exchanged for respiration, carbon dioxide isn’t stored as part of normal gas exchange, and nitrogen fixation is a separate biological process unrelated to breathing and gas exchange in humans.

Gas exchange centers on taking in oxygen for cellular use and getting rid of carbon dioxide produced by metabolism. In the lungs, oxygen moves from the air in the alveoli into the blood, while carbon dioxide moves from the blood into the alveoli to be exhaled. This exchange happens by diffusion across the respiratory membrane, driven by differences in partial pressures of the gases. So the two main processes are oxygen intake and carbon dioxide expulsion.

The other options don’t fit because nitrogen is not a key gas exchanged for respiration, carbon dioxide isn’t stored as part of normal gas exchange, and nitrogen fixation is a separate biological process unrelated to breathing and gas exchange in humans.