Concepts of Biology

Citation

Fowler, S., Roush, R., & Wise, J. (2013). Concepts of Biology. OpenStax. Free official edition: https://openstax.org/details/books/concepts-biology

Chapter Summary

Concepts of Biology is OpenStax's textbook for the one-semester introductory biology course for non-science majors, which the preface notes is for many students their only college science course. It has 21 chapters in six units, about 600 pages, plus appendices on the periodic table, geological time and the metric system. The preface says the book is "grounded on an evolutionary basis", aims at scientific literacy rather than facts and vocabulary, and follows the scope and sequence of most non-majors courses. Each chapter opens with a photograph and a short introduction and ends with key terms, a section-by-section summary, Visual Connection questions, review questions and critical thinking questions. Evolution Connection, Career Connection, Everyday Connection and Link to Learning boxes recur throughout.

Chapter 1: Introduction to Biology

Two sections: the themes and concepts of biology (properties of life, levels of organization, the diversity of life and phylogenetic trees, branches of biology) and the process of science (inductive and deductive reasoning, hypotheses and theories, basic and applied science, peer-reviewed publication).

Chapters 2–3: Chemistry of Life; Cell Structure and Function

Chapter 2 covers atoms and bonds, the properties of water and pH, and the four classes of biological macromolecules. Chapter 3 introduces microscopy and cell theory, compares prokaryotic and eukaryotic cells, tours the eukaryotic organelles, and explains the cell membrane and passive and active transport.

Chapters 4–5: How Cells Obtain Energy; Photosynthesis

Chapter 4 introduces energy and metabolism (thermodynamics, ATP, enzymes) and then glycolysis, the citric acid cycle and oxidative phosphorylation, fermentation, and links to other metabolic pathways. Chapter 5 opens by noting that every meal depends on photosynthesis, then covers its overview, the light-dependent reactions and the Calvin cycle.

Chapters 6–8: Reproduction at the Cellular Level; The Cellular Basis of Inheritance; Patterns of Inheritance

Unit 2 moves from the genome and the cell cycle, with sections on cancer and prokaryotic division, to sexual reproduction and meiosis, including errors of meiosis such as changes in chromosome number. It ends with Mendel's experiments, the laws of inheritance and their extensions (incomplete dominance, multiple alleles, linkage and similar departures from Mendelian ratios).

Chapters 9–10: Molecular Biology; Biotechnology

Chapter 9 opens with the everyday uses of DNA analysis (forensics, paternity, diagnosis) and covers DNA structure, replication, transcription, translation and gene regulation in five sections. Chapter 10 treats cloning and genetic engineering, biotechnology in medicine and agriculture, and genomics and proteomics, and introduces the ethical and social questions these raise.

Chapters 11–12: Evolution and Its Processes; Diversity of Life

Chapter 11 explains how populations change, the mechanisms of evolution, the evidence for it and speciation, and ends with a section on common misconceptions about evolution. Chapter 12 introduces classification and the construction of phylogenetic trees.

Chapters 13–15: Diversity of Microbes, Fungi, and Protists; Diversity of Plants; Diversity of Animals

Three survey chapters. The first covers prokaryotic diversity and the three domains (introduced through Carl Woese's work on ribosomal RNA), eukaryotic origins, protists and fungi. The second runs from the plant kingdom through seedless plants to gymnosperms and angiosperms. The third moves from the features of the animal kingdom through the invertebrate groups to the vertebrates.

Chapters 16–18: The Body's Systems; The Immune System and Disease; Animal Reproduction and Development

Unit 5 compresses animal physiology into one chapter with six sections: homeostasis and osmoregulation; the digestive system; the circulatory and respiratory systems; the endocrine system; the musculoskeletal system; and the nervous system. It is followed by chapters on viruses and innate and adaptive immunity (opening with the history of smallpox inoculation) and on animal and human reproduction and development. The preface notes the unit's focus on human anatomy and physiology.

Chapters 19–21: Population and Community Ecology; Ecosystems and the Biosphere; Conservation and Biodiversity

Unit 6 covers population demographics and growth, the human population and community ecology (opening with invasive Asian carp); energy flow, biogeochemical cycles and terrestrial and aquatic biomes; and the importance of biodiversity, the threats to it (with present extinction rates put at 500–1,000 times the background rate) and its preservation.

Key Concepts

Unit 1: The cellular foundation of life (Chapters 1–5)

• Properties of life: order, response to stimuli, reproduction, adaptation, growth, regulation, homeostasis and energy processing.
• Scientific method: forming and testing hypotheses; the difference between a hypothesis, a theory and a law.
• Cell theory and the membrane: all organisms are made of cells; the plasma membrane controls what enters and leaves.
• Cellular respiration and photosynthesis: the two complementary energy pathways on which life depends.

Units 2–3: Cell division, genetics and molecular biology (Chapters 6–10)

• Mitosis and meiosis: cell division for growth and repair, and the reduction division that produces gametes.
• Mendel's laws: segregation and independent assortment, and their extensions.
• From gene to protein: replication, transcription and translation, and the regulation of gene expression.
• Biotechnology: tools such as PCR, gel electrophoresis and cloning, and their medical and agricultural uses.

Unit 4: Evolution and diversity (Chapters 11–15)

• Natural selection: differential survival and reproduction leading to adaptation.
• Speciation: the formation of new species through reproductive isolation.
• Phylogenetic tree: a diagram of evolutionary relationships.
• Three domains: Bacteria, Archaea and Eukarya.

Units 5–6: Animal structure and ecology (Chapters 16–21)

• Homeostasis: maintaining internal conditions within a normal range.
• Innate and adaptive immunity: general defences and specific responses with memory.
• Population growth: exponential and logistic growth and carrying capacity.
• Biodiversity: the variety of life, its value and the threats to it.

Critical Analysis

Strengths

• Designed for its audience. The preface is explicit that non-majors need meaningful, readable material rather than "facts and vocabulary", and the chapter openers start from everyday matters: food and photosynthesis, DNA in forensics and paternity testing, invasive carp. The features on careers and everyday applications support the stated goal of scientific literacy.
• Manageable length. With 21 chapters and short chapters of two to six sections each, the whole book can realistically be covered, or nearly covered, in one semester. This is rarely true of majors' texts.
• Evolution and misconceptions. Evolution is presented as the framework of the book, and Chapter 11 includes a full section on common misconceptions about evolution, useful for students who meet the topic with doubts or mistaken ideas.
• Free and adaptable. The book is openly licensed (CC BY-NC-SA 4.0) and available free online and as a PDF. The preface encourages instructors to assign chapters in any order.

Limitations

• Thin on organismal physiology and absent on plant function. All animal organ systems share one chapter (Chapter 16), and there is no chapter on plant structure, transport or reproduction. Plants appear only in the photosynthesis chapter and the diversity survey of Chapter 14.
• An old book, lightly maintained. The original publication year is 2013. The preface still contains material that has not been updated: an invitation to a "Fall 2013 Pilot" of WileyPLUS, PowerPoint slides said to be "based on the extensive illustrations from College Physics", and an errata note that refers to change in "sociology". Some content in fast-moving areas, such as biotechnology and genomics, will also date.
• US-centred examples. Cases such as Asian carp in the rivers of Illinois and Missouri or the Karner blue butterfly in oak-pine barrens from Minnesota to New York assume an American reader.

Where It Fits in the Course

Concepts of Biology is the lightest general textbook in this course and the natural choice for non-majors or for anyone who wants a first pass through biology before a majors text. It shares material with OpenStax's Biology 2e: several chapter openings, from the brick-wall analogy for cells to the hummingbird, the arctic fox and the Asian carp, are the same or nearly so. A student who finds a topic hard in Biology 2e can read the matching chapter here first and then return. Biology 2e, Campbell Biology, Sadava and colleagues' Life: The Science of Biology and Freeman's Biological Science are all full two-semester majors' introductions. They give the depth this book deliberately leaves out, especially in genetics, physiology and plant biology.

The more specialized books in the course, Molecular Cell Biology by Lodish and colleagues and Milo and Phillips's Cell Biology by the Numbers, assume at least a majors-level first year and are not a direct next step from this book.

How to Use This Book

The book suits students taking biology as a general-education requirement and adult or self-directed learners. No college science is assumed; Chapter 2 supplies the chemistry needed.

A one-semester plan:

• Core: Chapters 1–3 (science, chemistry, cells), 6–9 (cell division, inheritance, molecular biology) and 11 (evolution). These carry the book's central ideas.
• Energy: Chapters 4–5 are the most technical. For a literacy-focused course, aim for the overview sections (4.1, 5.1) and the big picture of how respiration and photosynthesis connect, rather than every step.
• Choose by interest: Chapter 10 (biotechnology) and Chapter 17 (immune system and disease) connect most directly to health and current affairs. Chapters 12–15 (diversity) can be sampled. Chapters 19–21 (ecology and conservation) make a strong close to the course.

Read the chapter introduction for its everyday hook, work through the sections, then check yourself against the end-of-chapter summary. Use the Visual Connection questions to practise reading diagrams. Follow the Link to Learning animations for processes that are hard to picture. Answers to selected questions are available on the student resources page. Students who later move to a majors course can carry on with the corresponding chapters of Biology 2e.

Edition and Sources

This guide is based on Concepts of Biology (original publication 2013; senior contributing authors Samantha Fowler, Rebecca Roush and James Wise, with about thirty contributing authors and reviewers), read in the free official PDF linked from the OpenStax book page, https://openstax.org/details/books/concepts-biology (current PDF with 2026 copyright page, CC BY-NC-SA 4.0 licence). The guide draws on the preface (audience, coverage by unit, features, answers policy, resources), the full table of contents, and for all 21 chapters the chapter introductions, every section heading and the section-by-section chapter summaries, together with the titles of the Evolution, Career and Everyday Connection features.