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...

Everything you need to know about the respiratory system. The page includes modules regarding The Pathway, Breathing, Central Control of Breathing, Local Control of Breathing, and Diseases of the Lungs. Designed to be used as classroom...

This online biology book chapter offers definitions and descriptions of the nervous system's components.

This is an advanced level review of cladistic theory and methodology. Some sections are very dense but there are useful sections for teachers and students seeking a better understanding of the topic.