Skip to content
One Long Tail
Menu

Biology

113 lessons across 11 eras, from 350 BC to today. Tap any question to read its lesson.

  1. 350 BC – AD 1800

    Era 1: Naming the living

    1. Aristotle and the ladder of lifeHow are living things ordered?Completed
    2. Sorting the world of plantsHow are plants classified?Completed
    3. A fourteen-hundred-year mistakeWhy did a wrong book live so long?Completed
    4. Avicenna and the Canon of MedicineHow is disease classified?Completed
    5. Ibn al-Nafis and the pulmonary circulationDoes blood go from the heart to the lungs?Completed
    6. Vesalius maps the bodyWho tells the truth, the book or the corpse?Completed
    7. Harvey and the circulation of the bloodWhere does the blood go, and does it come back?Completed
    8. Linnaeus and binomial nomenclatureHow is every living thing given a single name?Completed
  2. 1600 – 1940

    Era 2: The invisible

    1. Hooke and the word "cell"What is inside a cork stopper?Completed
    2. Leeuwenhoek and the little animalsHow many living things are in a drop of water?Completed
    3. Malpighi and the capillariesWhere was Harvey's missing link?Completed
    4. Redi and the maggotsAre maggots born from meat?Completed
    5. Lind and the scurvy experimentWhat did history's first controlled experiment prove?Completed
    6. Spallanzani and the boiled brothCan life arise from nothing?Completed
    7. The Schleiden–Schwann cell theoryIs every living thing made of cells?Completed
    8. Virchow: every cell from a cellWhere does a cell come from?Completed
    9. Jenner and the birth of vaccinationCan a mild disease protect against a severe one?Completed
    10. Semmelweis and handwashingCan a doctor's hands kill?Completed
    11. Pasteur and the swan-neck flaskDo germs come from the air?Completed
    12. Lister and antisepsisWhy did surgery kill?Completed
    13. Koch and the agent of diseaseHow do you prove a microbe is the cause?Completed
    14. Beijerinck and the discovery of the virusCan a disease agent be smaller than a bacterium?Completed
    15. Eijkman, Funk and vitaminsCan a deficiency cause disease?Completed
    16. Fleming and penicillinHow did a mould kill bacteria?Completed
  3. 1800 – present

    Era 3: Evolution

    1. Cuvier and the language of fossilsAre there creatures that have died out?Completed
    2. Lyell and deep timeHow old is the Earth?Completed
    3. Lamarck and the giraffe's neckIs an acquired trait passed on?Completed
    4. The Beagle voyage and the finchesWhy is the same bird different on every island?Completed
    5. Natural selectionWho survives?Completed
    6. Wallace and simultaneous discoveryCan the same idea come to two people at once?Completed
    7. Sexual selection and the peacockWhy does useless beauty exist?Completed
    8. Darwin's orchids and coevolutionIs the insect shaping the flower?Completed
    9. The moths of the Industrial RevolutionCan evolution be seen with our own eyes?Completed
    10. Antibiotic resistanceCan bacteria evolve before our eyes?Completed
    11. Wegener and continental driftWhy is the same fossil on two separate continents?Completed
    12. The modern synthesisHow did Darwin and Mendel come together?Completed
  4. 1850 – 1980

    Era 4: The machine of life — physiology, nerves and development

    1. Claude Bernard and the internal environmentWhy is the body always the same temperature?Completed
    2. Cannon and homeostasisHow is balance maintained?Completed
    3. The Golgi stain and the visible nerveHow is a cell made visible?Completed
    4. Cajal and the neuron doctrineIs the brain one continuous network, or separate cells?Completed
    5. Sherrington and the synapseHow do cells talk without touching?Completed
    6. Loewi and chemical transmissionIs the nerve signal chemical?Completed
    7. Hodgkin–Huxley and the action potentialWhat travels along a nerve?Completed
    8. Pavlov and conditioningCan learning be measured?Completed
    9. Starling and hormonesDoes the body send messages to itself?Completed
    10. Banting, Best and insulinHow was diabetes stopped?Completed
    11. Landsteiner and blood groupsWhy did blood transfusions sometimes kill?Completed
    12. Muscle contraction and sliding filamentsHow does a muscle shorten?Completed
    13. Spemann and the organiserWho tells the embryo its shape?Completed
    14. The H.M. case and memoryWhere in the brain does memory live?Completed
    15. Hubel, Wiesel and how vision is processedHow does the brain make sense of what it sees?Completed
  5. 1770 – 1990

    Era 5: Inside the cell

    1. Van Helmont's willowWhat does a tree grow from?Completed
    2. Ingenhousz and photosynthesisDoes a plant clean the air?Completed
    3. The Calvin cycleHow does carbon become sugar?Completed
    4. The Krebs cycleHow is food turned into energy?Completed
    5. Mitchell and chemiosmosisHow is ATP made?Completed
    6. Margulis and endosymbiosisWere mitochondria once bacteria?Completed
    7. The electron microscope and organellesHow did the inside of the cell come into view?Completed
    8. Enzymes and the lock and keyHow do reactions speed up in the body?Completed
    9. The cell membrane and the fluid mosaicHow can a border be both closed and permeable?Completed
    10. Mitosis and cell divisionHow does one cell split in two?Completed
    11. HeLa cells and Henrietta LacksCan a cell be immortal?Completed
    12. Bishop, Varmus and oncogenesDoes cancer come from outside or from within?Completed
    13. Blackburn and telomeresHow many times can a cell divide?Completed
  6. 1860 – 1950

    Era 6: Heredity

    1. Mendel's peasDo traits blend, or hide?Completed
    2. Mendel forgotten and rediscoveredWhy does a good idea wait 35 years?Completed
    3. Miescher and nucleinWhat substance is in the nucleus?Completed
    4. The Sutton–Boveri chromosome theoryWhere do Mendel's units sit?Completed
    5. Morgan and fruit fliesIs heredity carried on chromosomes?Completed
    6. Linkage and the first gene mapCan the positions of genes be pinned down?Completed
    7. McClintock and jumping genesDoes a gene have to stay in place?Completed
    8. Hardy–WeinbergHow does a trait spread through a population?Completed
  7. 1940 – 1970

    Era 7: DNA

    1. Avery–MacLeod–McCartyIs the stuff of heredity protein or DNA?Completed
    2. The Hershey–Chase blender experimentWhat does a virus inject into a cell?Completed
    3. Chargaff's rulesWhy is there always as much A as T?Completed
    4. Franklin's Photo 51Can an X-ray show a molecule?Completed
    5. The Watson–Crick double helixHow does DNA copy itself?Completed
    6. The Meselson–Stahl experimentIs half of a copied helix old?Completed
    7. Cracking the genetic codeDo three letters make one amino acid?Completed
    8. The central dogmaWhich way does information flow?Completed
    9. Jacob–Monod and gene regulationWhen does a gene switch on?Completed
  8. 1890 – present

    Era 8: Immunity and defence

    1. Medawar and immune toleranceHow does the body tell itself apart from the foreign?Completed
    2. Burnet and clonal selectionHow does the body recognise an enemy it has never seen?Completed
    3. Tonegawa and antibody diversityHow do a limited number of genes make endless antibodies?Completed
    4. HIV and the collapse of immunityCan a virus strike the defences themselves?Completed
  9. 1970 – present

    Era 9: Writing life

    1. Restriction enzymes and recombinant DNACan DNA be cut and pasted?Completed
    2. Sanger sequencingHow is a genome read?Completed
    3. Mullis and PCRCan a million copies be made from a single molecule?Completed
    4. The Human Genome ProjectCan we read our own book?Completed
    5. Hox genes and the body planWhy is the same gene in both a fly and a human?Completed
    6. Gurdon, Dolly and cloningCan an adult cell be rewound?Completed
    7. Yamanaka and reprogrammingCan a cell forget its past?Completed
    8. CRISPRHow did a bacterium's defence become an editing tool?Completed
    9. Waddington, methylation and epigeneticsCan a gene's expression change without the gene changing?Completed
    10. mRNA vaccinesIs it possible to send the body a recipe?Completed
    11. Pääbo and the Neanderthal genomeCan DNA be read from a fossil?Completed
    12. AlphaFold and protein foldingCan a sequence reveal its own shape?Completed
  10. 1800 – present

    Era 10: The web of life

    1. Humboldt and the web of lifeIs nature the sum of its parts?Completed
    2. Darwin's earthwormsHow does the smallest creature make soil?Completed
    3. Lindeman and the food chainHow does energy flow through an ecosystem?Completed
    4. Tansley and the ecosystem conceptWhere does nature begin, and where does it end?Completed
    5. MacArthur–Wilson and island biogeographyHow many species can an island hold?Completed
    6. Alvarez and the asteroid extinctionWhat killed the dinosaurs?Completed
    7. Mass extinctionsHow many times has life nearly ended?Completed
    8. Rachel Carson and Silent SpringCan a book change the law?Completed
    9. Lucy and human originsWho stood up first?Completed
    10. The microbiomeAre the living things inside us part of us?Completed
    11. Goodall and the chimpanzeesIs using tools unique to humans?Completed
    12. Hamilton and kin selectionHow does altruism fit with evolution?Completed
  11. 1920 – present

    Era 11: The origin of life

    1. Oparin, Haldane and the primordial soupCan life arise from non-living chemistry?Completed
    2. The Miller–Urey experimentCan amino acids be made in a flask?Completed
    3. The RNA world hypothesisWhich came first — DNA or protein?Completed
    4. LUCA and the root of the tree of lifeWho is the common ancestor of all living things?Completed