Compliments of the University of Arizona, The Biology Project offers this online interactive resource. An excellent tool for the high school and introductory college classroom, this site provides detailed problem sets and tutorials, as well as guided tours for each lesson. Some content is available in Spanish. The human heart is the sole focus of the Franklin Institute Science Museum's site. This informative gem illustrates the heart's intricate operation as well as ways to nurture a healthy heart.
Teachers can also find enrichment activities to use in the classroom.
Grow a little further in the world of botany. Information on plant life and student activities are rooted here. Talks about Monarch butterfly anatomy, migration patterns, etc. Also compares and contrasts anatomies of butterflies and moths. Has curricula and activities for teachers and lets students track the movements of whales and other marine mammals based on global positioning satellites.