Why is diffusion insufficient to meet the oxygen requirements of multi - cellular organisms like humans?


  • Diffusion is the movement of a substance from an area of higher concentration to an area of lower concentration.
  • Diffusion occurs in multicellular organisms too, although it takes place on a cellular level .
  • Diffusion is a slow process. So, it will take a longer time over a much larger distance for oxygen to reach every cell of the body.
  • The volume of the human body is so large that oxygen cannot diffuse into all the cells in time to keep up with our metabolic needs.
  • Hence, diffusion is insufficient to meet the oxygen requirements of large multicellular organisms.


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Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 13 years and a teacher from the past 17 years. He teaches Science, Economics, Accounting and English at Teachoo