LIFE SCIENCE

Detailed explanation-1: -Diffusion is a type of passive transport, where molecules move from high concentration to low concentration. This means that the concentration of oxygen in the air must be higher than it is in the blood. The concentration of carbon dioxide is also different between the alveolar air and the blood of the capillary.

Detailed explanation-2: -Diffusion is a process in which the molecules interact and move from a region of higher concentration to a region of lower concentration. This process does not involve any requirement of energy since carbon dioxide can freely move through the cell membrane.

Detailed explanation-3: -In the process of diffusion, a substance tends to move from an area of high concentration to an area of low concentration until its concentration becomes equal throughout a space.

Detailed explanation-4: -Once the venous blood returns to the lungs, the carbon dioxide diffuses out of the bloodstream, through the capillaries, and into the alveoli from where it is expelled, during which time oxygen simultaneously binds with hemoglobin to be carried back to the tissues.