Question

By which of the following mechanism, oxygen is transported from lungs to cells?

• A. Diffusion
• B. Fascilitated diffusion
• C. Transpiration
• D. Osmosis

Answer 1

The correct option is A Diffusion

Alveoli are the primary sites of exchange of gases. Exchange of gases also occur between blood and tissues. O${}_2$ and CO${}_2$ are exchanged in these sites by simple diffusion mainly based on pressure/ concentration gradient. Solubility of the gases as well as the thickness of the membranes involved in diffusion are also some important factors that can affect the rate of diffusion.

Therefore, the correct answer is option A.