Question

in the single cell organism diffusion is sufficient to need all there requirement of food,exchange of gases, or removal of waste but it is not in the case of multicellular organism? explain the reason for this difference?

Answer 1

because multicellular organisms have specific part for for need all there requirement of food,exchange of gases, or removal of waste but it is not in the case of multicellular organism like human beings have different organ to different work like lungs for breathing .... or you know better