Science
Organisms & Life Processes
Conceptual
12–13 yrs
Gas Exchange & Breathing
气体交换与呼吸
Description
Describe the structure of the human gas exchange system (trachea, bronchi, bronchioles, alveoli) and explain how the mechanism of breathing — using pressure changes from rib and diaphragm movement — moves air in and out of the lungs
Mastery Evidence
- Labels a diagram of the lungs showing trachea, bronchi, bronchioles, and alveoli
- Explains that breathing in lowers air pressure in the chest and air rushes in
- Describes how the structure of alveoli (large surface area, thin walls, good blood supply) aids gas exchange
Assessment Prompt
If your child took a deep breath after running, could they explain what's happening in their lungs — how the air gets in, where the oxygen crosses into the blood, and how carbon dioxide leaves?
