Question

In single celled organisms diffusion is sufficient to meet all their requirements of food, exchange of gases or removal of wastes but it is not in case of multicellular organisms.
Explain the reason for this difference.​

Answer 1

Answer:

Diffusion is a very slow process. If multicellular organisms used diffusion to meet all requirements of food, exchange of gases or removal of wastes it would take too much of time for carrying even a single particle in the body of the organism and hence diffusion is a process only for unicellular organisms.