38. Animal Form and Function

The cells of an ant and an elephant are, on average, the same small size; an elephant just has more of them. What is the main advantage of small cell size? (Explain your reasoning.) a. A small cell has a larger plasma membrane surface area than does a large cell. b. Small cells can better take up sufficient nutrients and oxygen to service their cell volume. c. It takes less energy to make an organism out of small cells. d. Small cells require less oxygen than do large cells.

______ refers to the protection of the internal environment against the harms of changes in the external environment.