CK-12 Foundation
Ck 12: Life Science: Seasonal Changes in Plants
[Free Registration/Login may be required to access all resource tools.] Have you seen the leaves of plants change colors? During what time of year does this happen? What causes it to happen? Plants can sense changes in the seasons....
CK-12 Foundation
Ck 12: Life Science: Plant Hormones
[Free Registration/Login may be required to access all resource tools.] Plants may not move, but that does not mean they don't respond to their environment. Plants can sense gravity, light, touch, and seasonal changes. Learn more about...
Annenberg Foundation
Annenberg Learner: Journey North: Tulip Gardens
Track tulip growth as the season changes from winter to spring. See how temperature, rainfall, and sunshine affect growth and help scientists look for patterns of climate change.