Curriculum resources can be expensive—but not this one. An online textbook offers informational text for a complete high school Biology course. Topics include energy flow, body system, genetics, and evolution.

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...

Physical and biological factors affect everyday living. Scholars explore electromagnetic forces, motion, the rock cycle, and geological changes. They examine cells as the building blocks of life and how organisms reproduce using images...

Explore a variety of science concepts in an interactive textbook created for middle school scholars. A lengthy table of contents takes readers to pages comprised of a subject overview, outline, and summary. Follow links further to find...

Get up close and personal with beautiful and sometimes dangerous insects in an exciting eBook activity! Pupils practice geography skills by reading a map with the location of six different insects. Scientists read about each insect,...

Are spiders related to crabs? Study the order of arthropods with a reading selection about animal diversity. It provides details about each class within the order, as well as vivid pictures and explanatory charts. 

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...

These pages are part of a site called "Evolution," that accompanies a textbook by the same name. Mark Ridley is the author, and in this section he discusses the evidence for evolution.

This site is a section part of a website that accompanies "Evolution," a textbook by Mark Ridley. Here he covers homologous structures, using them as evidence for evolution.

Discover the evolution and change of plants over time.

Examine Charles Darwin's voyage on the HMS Beagle and his ideas about evolution and natural selection.

Explore the evidence for evolution: anatomy, molecular biology, biogeography, fossils, & direct observation.

Learn about virus evolution and genetic variation in viruses.

When a population is in Hardy-Weinberg equilibrium, it is not evolving. Learn how violations of Hardy-Weinberg assumptions lead to evolution.

Discover how Charles Darwin developed the theory of evolution through his observations in the Galapagos Islands.

Explore the evolution and ecology of amphibians.

The entire text of Charles Darwin's book, The Origin of Species is available on this site. This link is specifically for the chapter that discusses embryology as evidence for evolution.

A good site that goes over the similarities and differences of reptiles and birds. Good look at the issue from a seemingly neutral view.

This is Chapter One from "Becoming Human: Evolution and Human Uniqueness," by Ian Tattersall. This chapter presents recent findings about the art and artifacts of early humans, and what those artifacts tell us about the intellectual...

RCN offers information about plants, including the evolution and classification of different groups.

See how scientists trace species through their evolutionary relationships.

Learn about several different forms of evolutionary evidence.

Use the left-hand toolbar of this site to investigate an online textbook for the language of design. It provides visual examples and explanations of line, form, color, color psychology, texture, balance, proportion and many more...

Easy-to-understand notes and large graphics on the endocrine system include the evolution of the endocrine system and feedback cycles. Hormones and the nervous system are also discussed.