| A | B |
|---|
| The basic unit of all living things | cell |
| A factor that limits cell size | surface-to-volume ratio |
| How surface area-to-volume ration limits cell growth | volume grows faster than surface area, which makes diffusion slow |
| How diffusion limits cell growth | as cell grows, nutrients cannot move efficiently through cell membrane |
| How DNA limits cell growth | it gets overloaded and can't keep up |
| Why unicellular organisms cannot grow very large | the diffusion of nutrients into the cell's interior would be too slow |
| What separates the inside of a cell from the environment | plasma membrane |
| Another factor that limits cell size | diffusion |
| A different factor that limits cell size | DNA |
