Most people know that sunlight is necessary for life to exist.  Some interesting investigations can be done in the life science classroom regarding the sun.  How does the length of daylight hours or photoperiod affect biological systems?  What makes the leaves change color in the fall?  How does the absence of light affect a living creature?  The activities presented here allow students to model effects that the sun has on all living systems.

Leaf Color Change Activities:  Various activities that show the effect of photoperiod on leaf color change.  There are Mathematica® activities, Excel® graphs, and notes for the teacher.

Plant Pigment Separation Activity:  A lab investigation of plant pigments.

Hamster Activity Rhythms: A live animal experiment.

Human and Animal System Research:  An independent research project on the physiological and behavioral effects of changes in photoperiod.