How DNA, RNA and proteins store and use life's instructions.
12 key ideas · 3 labs
Fields of biology
Fifteen fields, one living world. Each field page explains what the field studies at your reading level, the questions it asks, its key ideas and the labs where you can explore them.
The structures and machinery inside the basic unit of life.
13 key ideas · 2 labs
How traits are inherited and how genes vary.
13 key ideas · 3 labs
The chemistry of life: enzymes, energy and metabolism.
11 key ideas · 3 labs
Bacteria, archaea, fungi, protists and viruses.
11 key ideas · 2 labs
How the body recognizes and fights infection.
10 key ideas · 2 labs
Neurons, signals and the brain.
6 key ideas · 1 lab
How the human body is built and kept in balance.
11 key ideas · 2 labs
How plants capture light, move water and grow.
10 key ideas · 3 labs
How living things interact with each other and their environment.
11 key ideas · 3 labs
How life changes over generations.
10 key ideas · 3 labs
Life in the ocean, from the sunlit surface to deep-sea vents.
8 key ideas · 2 labs
Using living systems to make medicines, tools and food.
12 key ideas · 3 labs
Designing and building new biological systems.
6 key ideas · 2 labs
Computing with biological data.
8 key ideas · 3 labs
The borders between fields are loose. A question about one protein can involve molecular biology, biochemistry, genetics and medicine at once. See how the ideas connect in the knowledge graph.
Sources & further reading
Good starting points for each field: open textbooks, reviews and agency pages. Field introductions are our own overviews; specific claims are sourced on the concept and lab pages. How we choose and check sources.
Molecular Biology of the Cell (4th edition) (opens the original in a new tab)
Alberts B, Johnson A, Lewis J, et al. (2002). Garland Science.
Free to read on NCBI Bookshelf. Standard reference for cell structure and molecular biology.
TextbookEducationalCentral dogma of molecular biology (opens the original in a new tab)
Crick F (1970). Nature 227:561-563.
Crick's own statement of what the central dogma does and does not claim.
Historical paperPerspectiveBiology 2e (opens the original in a new tab)
OpenStax (2018). OpenStax, Rice University.
Free introductory college textbook.
TextbookEducationalLicence: CC BY-NC-SA 4.0 (linked, not reused)
The Cell: A Molecular Approach (2nd edition) (opens the original in a new tab)
Cooper GM (2000). Sinauer Associates.
Free to read on NCBI Bookshelf.
TextbookEducationalEndosymbiosis and eukaryotic cell evolution (opens the original in a new tab)
Archibald JM (2015). Current Biology 25:R911-R921.
Peer-reviewedReviewExperiments on Plant Hybrids by Gregor Mendel (opens the original in a new tab)
Abbott S, Fairbanks DJ (2016). Genetics 204:407-422.
A modern English translation of Mendel's 1866 paper.
Peer-reviewedTranslationWhat are the different ways a genetic condition can be inherited? (opens the original in a new tab)
MedlinePlus Genetics. MedlinePlus Genetics. U.S. National Library of Medicine, NIH.
ReferenceGovernment sourceEducationalThe original Michaelis constant: translation of the 1913 Michaelis-Menten paper (opens the original in a new tab)
Michaelis L, Menten ML, Johnson KA, et al. (2011). Biochemistry 50:8264-8269.
Peer-reviewedTranslationPrinciples that govern the folding of protein chains (opens the original in a new tab)
Anfinsen CB (1973). Science 181:223-230.
Nobel lecture: a protein's sequence determines its folded structure.
Historical paperPrimary researchCoupling of phosphorylation to electron and hydrogen transfer by a chemi-osmotic type of mechanism (opens the original in a new tab)
Mitchell P (1961). Nature 191:144-148.
The chemiosmotic hypothesis for how cells make ATP.
Historical paperTheory or modelMicrobiology (opens the original in a new tab)
OpenStax (2016). OpenStax, Rice University.
TextbookEducationalLicence: CC BY-NC-SA 4.0 (linked, not reused)
Medical Microbiology (4th edition) (opens the original in a new tab)
Baron S (editor) (1996). University of Texas Medical Branch at Galveston.
Free to read on NCBI Bookshelf. Older edition; check newer sources for current treatment information.
TextbookEducational
Show 27 more sourcesHide 27 sources
Towards a natural system of organisms: proposal for the domains Archaea, Bacteria, and Eucarya (opens the original in a new tab)
Woese CR, Kandler O, Wheelis ML (1990). Proceedings of the National Academy of Sciences 87:4576-4579.
Peer-reviewedPerspectiveAntimicrobial resistance (fact sheet) (opens the original in a new tab)
World Health Organization. who.int. World Health Organization.
Fact sheetIntergovernmental sourceImmunobiology: The Immune System in Health and Disease (5th edition) (opens the original in a new tab)
Janeway CA Jr, Travers P, Walport M, et al. (2001). Garland Science.
Free to read on NCBI Bookshelf.
TextbookEducationalAnatomy and Physiology 2e (opens the original in a new tab)
OpenStax (2022). OpenStax, Rice University.
TextbookEducationalLicence: CC BY-NC-SA 4.0 (linked, not reused)
Vaccines and immunization: What is vaccination? (opens the original in a new tab)
World Health Organization. who.int. World Health Organization.
ReferenceIntergovernmental sourceEducationalNeuroscience (2nd edition) (opens the original in a new tab)
Purves D, Augustine GJ, Fitzpatrick D, et al. (2001). Sinauer Associates.
Edited textbook, free to read on NCBI Bookshelf.
TextbookEducationalBrain Basics: Know Your Brain (opens the original in a new tab)
National Institute of Neurological Disorders and Stroke. ninds.nih.gov. National Institute of Neurological Disorders and Stroke, NIH.
ReferenceGovernment sourceEducationalA quantitative description of membrane current and its application to conduction and excitation in nerve (opens the original in a new tab)
Hodgkin AL, Huxley AF (1952). Journal of Physiology 117:500-544.
The equations behind this site's action potential simulator.
Historical paperPrimary researchRevised estimates for the number of human and bacteria cells in the body (opens the original in a new tab)
Sender R, Fuchs S, Milo R (2016). PLOS Biology 14:e1002533.
About 3.0 × 10^13 human cells and 3.8 × 10^13 bacteria in a 70 kg reference adult.
Peer-reviewedPrimary researchAnalysis of the genome sequence of the flowering plant Arabidopsis thaliana (opens the original in a new tab)
Arabidopsis Genome Initiative (2000). Nature 408:796-815.
Peer-reviewedPrimary researchPrimary production of the biosphere: integrating terrestrial and oceanic components (opens the original in a new tab)
Field CB, Behrenfeld MJ, Randerson JT, et al. (1998). Science 281:237-240.
Global net primary production of about 105 petagrams of carbon per year, split roughly evenly between land and ocean.
Peer-reviewedPrimary researchSummary for policymakers of the global assessment report on biodiversity and ecosystem services (opens the original in a new tab)
IPBES (2019). Zenodo. Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.
Consensus reportIntergovernmental sourceEvolution (opens the original in a new tab)
National Human Genome Research Institute. Talking Glossary of Genomic and Genetic Terms. National Human Genome Research Institute, NIH.
ReferenceGovernment sourceEducationalEvolution of character displacement in Darwin's finches (opens the original in a new tab)
Grant PR, Grant BR (2006). Science 313:224-226.
Peer-reviewedPrimary researchHow far does light travel in the ocean? (opens the original in a new tab)
NOAA National Ocean Service. oceanservice.noaa.gov. National Oceanic and Atmospheric Administration.
Fact sheetGovernment sourceGlobal warming and recurrent mass bleaching of corals (opens the original in a new tab)
Hughes TP, Kerry JT, Álvarez-Noriega M, et al. (2017). Nature 543:373-377.
Peer-reviewedPrimary researchRecombinant DNA Technology (opens the original in a new tab)
National Human Genome Research Institute. Talking Glossary of Genomic and Genetic Terms. National Human Genome Research Institute, NIH.
ReferenceGovernment sourceEducationalHuman genome editing: a framework for governance (opens the original in a new tab)
World Health Organization (2021). WHO publications. World Health Organization. Published 2021-07-12.
GuidanceIntergovernmental sourceHuman Genome Editing: Science, Ethics, and Governance (opens the original in a new tab)
National Academies of Sciences, Engineering, and Medicine (2017). The National Academies Press.
Consensus reportA brief history of synthetic biology (opens the original in a new tab)
Cameron DE, Bashor CJ, Collins JJ (2014). Nature Reviews Microbiology 12:381-390.
Peer-reviewedReviewConstruction of a genetic toggle switch in Escherichia coli (opens the original in a new tab)
Gardner TS, Cantor CR, Collins JJ (2000). Nature 403:339-342.
Two mutually repressing genes form a switch with two stable states.
Peer-reviewedPrimary researchA synthetic oscillatory network of transcriptional regulators (opens the original in a new tab)
Elowitz MB, Leibler S (2000). Nature 403:335-338.
The repressilator: three repressors wired in a loop produce oscillations.
Peer-reviewedPrimary researchDesign and synthesis of a minimal bacterial genome (opens the original in a new tab)
Hutchison CA 3rd, Chuang RY, Noskov VN, et al. (2016). Science 351:aad6253.
Peer-reviewedPrimary researchBioinformatics (opens the original in a new tab)
National Human Genome Research Institute. Talking Glossary of Genomic and Genetic Terms. National Human Genome Research Institute, NIH.
ReferenceGovernment sourceEducationalBasic local alignment search tool (opens the original in a new tab)
Altschul SF, Gish W, Miller W, et al. (1990). Journal of Molecular Biology 215:403-410.
BLAST, the fast heuristic search used to compare sequences against databases.
Peer-reviewedPrimary researchUniProt: the Universal Protein Knowledgebase in 2023 (opens the original in a new tab)
UniProt Consortium (2023). Nucleic Acids Research 51:D523-D531.
Peer-reviewedPrimary researchHighly accurate protein structure prediction with AlphaFold (opens the original in a new tab)
Jumper J, Evans R, Pritzel A, et al. (2021). Nature 596:583-589.
Peer-reviewedPrimary research