Name ____________________________________
Pgs 241-243
1. Why are cells small? Give 2 reasons and explain.
2.
What happens to the surface area to volume ratio as the surface area increases?
Explain why how this is an important idea for why cells are small.
pgs 250-252
1. Explain how cells know when to stop dividing?
2. Explain how this (from number 1) is important with cuts in skin and fractures in
bones.
3. What is cyclin and what does it do?
4. What are internal regulators and what do they do?
5. Explain two examples of what internal regulators do.
6. What are external regulators and what do they do?
7. Explain two examples of how external regulators are important.
8. In terms of internal regulators, external regulators, and the cell cycle, explain what
cancer is and why it is a problem.