UNIT OVERVIEW

Every cell in your body needs oxygen to release energy from food. Every cell also produces carbon dioxide as waste. But how do these gases move between your body and the air around you?

This unit explores gaseous exchange—the movement of oxygen and carbon dioxide between living organisms and their environment.

You will learn:

• The difference between breathing, gaseous exchange, and cellular respiration
• What makes a good gas exchange surface
• How different organisms (plants, earthworms, insects, fish, and mammals) exchange gases
• How the human respiratory system works
• How diseases like TB, asthma, and emphysema affect breathing
• Why altitude affects how well we breathe