Which of the following is a major cause of the size limits for certain types of cells?

A. the difference in plasma membranes between prokaryotes and eukaryotes

B. the evolution of larger cells after the evolution of smaller cells

C. the observation that longer cells usually have greater cell volume

D. the need for a surface area of sufficient area to allow the cell's function

E. the evolution of eukaryotes after the evolution of prokaryotes

D. the need for a surface area of sufficient area to allow the cell's function

Explanation:

Many cellular functions such as the exchange of substances and respiratory gases, absorption of nutrients, cell-cell communication, etc. require the cells to have a sufficient surface area. A small cell has a larger surface area to volume ratio and therefore, maintains a higher rate of exchange of substances. As the cell increases in size, the surface area grows less than its volume. Therefore, the surface area required to perform the cellular functions puts an upper limit on the cell size.

Cells maintain the required surface area by dividing and/or by developing folding or projections on the surface. For instance, the cells in the wall of the small intestine require to maintain a higher surface area for nutrient absorption. Therefore, the cells of the wall of the small intestine develop microvilli to have a larger surface area which in turn supports a relatively higher rate of absorption.