For them a circulatory system (representing all that is left of the sea that once bathed individual cells) is required. ... For example, the fact that we have a respiratory system does not mean that our cells no longer engage in cellular respiration. ... engulfed digestive and circulatory systems 02 and C02 exchange diffusion respiratory and circulatory systems N wastes diffusion excretory system support buoyedanbsp;...
|Title||:||Introduction to Biology|
|Author||:||Donald J. Farish|
|Publisher||:||Gareth Stevens Publishing - 1984-01-01|