Question

capillaries exchange gases with the cells surrounding them. which of the following correctly represents the gas exchange represented in the diagram? 1 - carbon dioxide; 2 - oxygen 1 - hydrogen; 2 - oxygen 1 - oxygen; 2 - carbon dioxide 1 - carbon dioxide; 2 - nitrogen

Explanation:

During gas exchange in capillaries, oxygen ($O_2$) diffuses from the capillary to the surrounding cells (as cells need oxygen for cellular respiration). Carbon dioxide ($CO_2$), a waste product of cellular respiration, diffuses from the cells into the capillary. So, 1 should be oxygen and 2 should be carbon dioxide.

Answer:

1 - oxygen; 2 - carbon dioxide