why is diffusion insufficient to meet the oxygen requirements in multicellular organisms like humans?
Answers
As we know that human are made up of millions of cell and many cells made tissues. These tissues make organs and then organ system. Every cell is not with direct contact to outer environment. So it is not possible to get sufficient amount of oxygen to the body from diffusion.
In multicellular organisms like human beings diffusion is insufficient to meet the oxygen requirements of the body because of the following reasons :
• Diffusion is a very very slow process. Thus it can't fulfil the requirements of our body.
• The oxygen in human beings will have to travel last distances inside our body to reach each and every part of the cells.
• The volume of human body is so big that oxygen cannot diffuse into all the internal cells of the human body quickly.
• Also this is the reason for why the respiratory pigments are present in multicellular organisms also.