This biology question covers important biological concepts and processes. The step-by-step explanation below helps you understand the underlying mechanisms and reasoning.
ScanSolve AI Answer
The correct diagram is B. In the lungs, gas exchange occurs between the alveoli and the capillaries. Oxygen (O₂) from the inhaled air in the alveoli diffuses into* the blood. Carbon dioxide (CO₂), a waste product carried by the blood, diffuses out* of the blood into the alveoli to be exhaled. Diagram (B) correctly shows the arrow for O₂ pointing from the alveolus into the blood, and the arrow for CO₂ pointing from the blood into the alveolus.