How diverse are living things? Individuals explore topics such as cells as the foundation for life, cell division and genetics, molecular biology, and animal reproduction using an open resource Biology textbook. They learn key terms...

An eight-unit electronic textbook provides a guide to AP® Biology. Each of the 28 chapters include an introduction, multiple lessons, a summary, review questions, and test prep questions. Teachers see how each lesson connects to a big...

How does an organism go from a single cell to something as complex as a frog, fly, or human being? Learn the basic principles of development.