1. Mutations to DNA cause changes in organisms. Explain why this might be important to the survival of a spcies?

2. Why is it important to be protected with a lead shield when you are getting dental X rays?

3. Why can suntanning be dangerous for a skin cell?

2 answers

help is greatly appreciated!~!
1.
http://en.wikipedia.org/wiki/Mutation
2.
http://en.wikipedia.org/wiki/Lead_shielding
3.
http://en.wikipedia.org/wiki/Skin_cancer
http://www.hawaiiantan.com/qvc.htm