1. Explain why restriction enzyme and gel electrophoresis are valuable tools in the molecular biology lab.

2. What factors (aside from size) could influence the migration speed of dna fragments in gel electrophresis?

3. The respiratory centers that control ventilation of the lungs in mammals are located in the what?

4. Under what conditions would you use a 2% agarose gel, rather than one that is 0.8%?