cK-12 Biology Flexbook

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cK12 Biology 1 – flexbook

This page offers convenient access to Biology I flexbook. While the cK-12 chapters do not always directly correspond Honeycutt Science topic numbers, our site’s topic IDs are presented as convenient hyperlinks in italics following the cK-12 chapter name.

For example: Chapter 4 (Photosynthesis) and Topic 15 (Plant Cells) cover similar content, but they are only complementary – not identical. In this example, both include distinctions of plant cells compared to animal cells. But, Chapter 4 describes and illustrates how chloroplasts convert light energy to chemical energy, whereas  topic 15 does not dive into those details. Conversely, Topic 15 includes discussion and concepts of bio-engineering in plants. Chapter 4 does not mention bio-engineering. Together, Chapter 4 and Topic 15 provide similar and complementary content with duplication only in the most significant areas.

Note: If printed, the 26 chapters (pdf files below) from cK-12 Biology flexbook contain 1,391 total pages. For comparison, most commercially available high school biology text books have less than 1,000 total pages. Chapters 1-18 plus the Appendix cover content in a typical high school Biology textbook. Chapters 19-25 cover content typically available in an introduction to physiology/anatomy (an upper-level high school life sciences course).

CAUTION: The pdf file attachments provided below are very large. They may take several seconds to several minutes to download. For users concerned about data-usage or data charges, these files may not be appropriate for downloading. Approximate file size for each chapter is provided at the bottom of this page.

Approximate file size (megabytes) of each chapter

  • Chapter 01 – Foundations of Science.pdf…..(5.7 megabytes)
  • Chapter 02 – Chemical Basis of Life.pdf…..(2.7 megabytes)
  • Chapter 03 – Cell Structure and Function.pdf…..(5.7 megabytes)
  • Chapter 04 – Photosynthesis.pdf…..(4.6 megabytes)
  • Chapter 05 – Cellular Respiration.pdf…..(4.3 megabytes)
  • Chapter 06 – Cell Division and Reproduction.pdf…..(1.7 megabytes)
  • Chapter 07 – Mendelian Genetics.pdf…..(3.9 megabytes)
  • Chapter 08 – Molecular Genetics.pdf…..(5.2 megabytes)
  • Chapter 09 – Human Genetics.pdf…..(1.1 megabytes)
  • Chapter 10 – Biotechnology.pdf…..(1.8 megabytes)
  • Chapter 11 – History of Life.pdf…..(4.6 megabytes)
  • Chapter 12 – Evolutionary Theory.pdf…..(4.3 megabytes)
  • Chapter 13 – Evolution in Populations.pdf…..(9.8 megabytes)
  • Chapter 14 – Classification.pdf…..(12.1 megabytes)
  • Chapter 15 – Principles of Ecology.pdf…..(4.1 megabytes)
  • Chapter 16 – Biomes Ecosystems and Communities.pdf…..(20.1 megabytes)
  • Chapter 17 – Populations.pdf…..(3 megabytes)
  • Chapter 18 – Ecology and Human Actions.pdf…..(6.5 megabytes)
  • Chapter 19 – The Human Body.pdf…..(0.8 megabytes)
  • Chapter 20 – Nervous and Endocrine Systems.pdf…..(3.5 megabytes)
  • Chapter 21 – Skeletal Muscular and Integumentary Systems.pdf…..(4.3 megabytes)
  • Chapter 22 – Circulatory and Respitory Systems.pdf…..(2.4 megabytes)
  • Chapter 23 – Digestive and Excretory Systems.pdf…..(1.5 megabytes)
  • Chapter 24 – Immune System and Disease.pdf…..(0.9 megabytes)
  • Chapter 25 – Reproductive System and Human Development.pdf…..(1.4 megabytes)
  • Chapter 26 – Appendix.pdf…..(0.4 megabytes)

CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web based collaborative model termed the “FlexBook,” CK-12 intends to pioneer the generation and distribution of high quality educational content that will serve both as core text as well as provide an adaptive environment for learning. Copyright ©2009 CK-12 Foundation This work is licensed under the Creative Commons Attribution-Share Alike 3.0 United States License.

To view a copy of this license, visit http://creative or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.