Which dictates our existence? Is it our genetic makeup or the environment we grow up in? Kevin Davies offers an update on this long-standing debate, from the NOVA: "Cracking the Code of Life" Web site.

Just as the title claims, here are fifty different ways to respond to a book. Most can be adapted to all grade levels.

Ninth graders read National Geographic's "Teenage Brains" by David Dobbs and various informational texts about the development of the teenage brain to understand the factors that ultimately dictate teens' decision-making and behavior.