Question

Describe a cell which effectively uses diffusion as a means to move materials in and out. Suggest how being small helps cells survive, and being made of many small cells helps large organisms maintain homeostasis.
I don't know of any cells which effectively uses diffusion as a means to move materials in and out.

Answer 1

A cell that uses diffusion for primary material interchange is the Red Blood Cell. Being small increases overall surface area and therefore, more material can be diffused. Also, the cell is able to go into the tiniest of capillaries and still function effectively. Homeostasis is the body's ability to maintain a constant internal environment. By having multiple cells, the various internal variables (blood sugar, sodium level, urea concentration etc.) can by controlled by one type of cell and therefore, because that type of cell only has to worry about 1 variable it can do its job effectively and efficiently