The Total solution for NCERT class 6-12
Oxygen and Carbon-di-oxide is transported in human being via blood stream. Oxygen is carried to the cells whereas carbon-di-oxide is carried away from the cells. Exchange of gases takes place between the alveoli of lungs and the surrounding blood capillaries. Oxygen is absorbed by the blood capillaries from the lungs alveoli by diffusion while carbon-dioxide is absorbed by the lungs alveoli from blood capillaries by diffusion.