Question

In unicellular organisms, diffusion is sufficient to meet all their requireents, but in multicellular orgnaism,, it is not. Explain with a suitable example

Answer 1

Answer: This is because, in multicellular organisms all the cells may not be direct contact with the surrounding environment

Eg: In case of amoeba its entire body is in contact with the environment . But in humans it is not applicable.

Explanation:

Answer 2

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.