1. Do cells have size limits?

2.  Cells can range from 2µm to 200µm (10⁻⁶m).  µm = millionth of a meter or 0.000001m  Most eukaryotic cells are about 10µm.  Not visible with the naked eye. Let's put this into perspective!!

3.  This means that an infant’s cells are the same size as an adult or teenager.  Eukaryote cells all have similar sizes.  They increase cell numbers to grow.  Why do Eukaryotes have so many cells? Why do we not have just 1 cell or 10 cells?  There is still lots of cell variety!!!

4. Muscle Cells Epithelial Cells (skin) Nerve Cells

5.  These cells may look very different, but are all about the same size.  Shapes may change, but sizes are constrained!! Why?? Red and White Blood Cells Plant cells

6.  Microvilli in the small intestine  Branches in Lungs  Anemones many tentacles  Trees and their broad/flat leaves

7.  Increasing Surface Area for individual cells is also important.  Consider : ◦ What are all these adaptations trying to accomplish for the organism?

8.  What measurements represent the cell membrane? The cytoplasm?  Does the distance from the center increase or decrease from model to model?  Which cell is best able to interact with its environment?  How can cells increase their total surface area to volume ratio?