A free IB lesson every day, by syllabus topic. Not affiliated with the International Baccalaureate. https://theibaxolotl.com/ 2026-10-15T13:30:00-04:00 TheIBAxolotlhttps://www.youtube.com/@TheIBAxolotl?sub_confirmation=1 https://theibaxolotl.com/lessons/ib-computer-science-cpu-alu-cu-registers-mar-vs-mdr-MmgSi6862Rw.html2026-10-15T13:30:00-04:00

IB Computer Science A1.1, computer hardware and operation: the components of the CPU (part 1 of 10, for SL and HL). What the ALU, the control unit and the registers PC, MAR, MDR, IR and accumulator do, and how the address bus, data bus and control bus connect the CPU to memory, following one instruction from memory into the CPU. Includes an eight mark exam-style question solved step by step.

https://theibaxolotl.com/lessons/free-radical-substitution-ib-chemistry-6-mark-mechanism-aGTfEROp7dA.html2026-10-14T20:30:00-04:00

IB Chemistry Reactivity 3.3, electron sharing reactions: radical substitution of an alkane with a halogen (part 2 of 5, for SL and HL). The three steps of the mechanism, initiation, propagation and termination, with every equation for methane and chlorine, and why one chlorine radical starts a chain reaction. Includes a six mark exam-style question solved step by step.

https://theibaxolotl.com/lessons/protons-neutrons-electrons-in-7-min-qFXYGCOXVzM.html2026-10-14T13:30:00-04:00

IB Chemistry Structure 1.2, the nuclear atom: protons, neutrons and electrons (part 1 of 4, for SL and HL). The three particles with their relative masses and charges, what the gold foil experiment shows, atomic number and mass number, and how to count the particles in any atom or ion. Includes a six mark exam-style question solved step by step.

https://theibaxolotl.com/lessons/natural-selection-fitness-in-8-min-6-marks-tJFrisb2eDY.html2026-10-13T20:30:00-04:00

Biotic and abiotic selection pressures, what fitness really means, and why only heritable traits can evolve, with finches, peppered moths and bacteria as examples. Includes a six mark exam-style question solved step by step. Part 2 of 8 on IB Biology D4.1 Natural selection, for SL and HL.

https://theibaxolotl.com/lessons/hydrogen-bonds-in-water-in-7-min-6-marks-F-zQKnjSUNM.html2026-10-13T13:30:00-04:00

Why water is the medium for life, why the water molecule is polar, and how hydrogen bonds form between water molecules. Includes a six mark exam-style question with a drawing, solved step by step. Part 1 of 6 on IB Biology A1.1 Water, for SL and HL.

https://theibaxolotl.com/lessons/integration-basics-6-mark-paper-1-in-9-min-q7ZpZIxb3Og.html2026-10-12T20:30:00-04:00

Integration from zero: why it undoes differentiation, the reverse power rule, and how one point on the curve gives you the constant + C. Includes a six mark Paper 1 style question solved step by step, without a calculator. Part 1 of 7, for IB Mathematics: Analysis and Approaches, SL and HL.

https://theibaxolotl.com/lessons/3-log-laws-in-8-minutes-7-mark-paper-1-YG-Th955LJA.html2026-10-12T13:30:00-04:00

What a fractional exponent means, and the three laws of logarithms: product, quotient and power. Includes a seven mark Paper 1 style question solved step by step, without a calculator. Part 2 of 7, for IB Mathematics: Analysis and Approaches, SL and HL.

https://theibaxolotl.com/lessons/extended-essay-criteria-5-checks-30-marks-g3qrrhc8i6c.html2026-10-11T20:30:00-04:00

A final pass for your IB extended essay, one check per criterion: framework, knowledge and understanding, analysis and line of argument, discussion and evaluation, and reflection. Plus what counts towards the 4,000 words and two quick checks for your references. For IB Diploma students in their second year (IB2).

https://theibaxolotl.com/lessons/plan-your-ib-week-in-7-minutes-5-deadlines-3-moves-wWdurqbWQyg.html2026-10-11T13:30:00-04:00

Five deadlines, one week: a planning problem solved step by step. List every deadline with its hours, work backwards from each one, and find the crunch before it finds you. Then how to use each study hour: short, spaced sessions where you test yourself. For IB Diploma students in their first year (IB1); it works in IB2 as well.

https://theibaxolotl.com/lessons/distance-vs-displacement-in-6-minutes-10-mark-paper-2-breakdown-a3qbnSMoKTw.html2026-10-10T20:30:00-04:00

A ten mark Paper 2 style kinematics question, broken down mark by mark: when a particle changes direction, why maximum speed is not maximum velocity, and why total distance needs the absolute value. Calculator steps included. For IB Mathematics: Analysis and Approaches, SL and HL.

https://theibaxolotl.com/lessons/completing-the-square-9-mark-paper-1-in-7-min-enV0EFZpKdc.html2026-10-10T13:30:00-04:00

A nine mark Paper 1 style question on quadratics, solved line by line with no calculator: complete the square, read the vertex and the axis of symmetry, and use the word “hence” to solve the equation. For IB Mathematics: Analysis and Approaches SL (HL students need it too).

https://theibaxolotl.com/lessons/natural-selection-explained-6-mark-question-u3vUYg--kn0.html2026-10-09T20:30:00-04:00

IB Biology D4.1, natural selection: how natural selection works (part 1 of 8, for SL and HL). What natural selection is, where variation comes from (mutation, meiosis and fertilization), and why overproduction of offspring leads to competition. Includes a six mark exam-style question solved step by step. Part 1 of 8 on IB Biology D4.1 Natural selection.

https://theibaxolotl.com/lessons/radicals-homolytic-fission-explained-2FZO6aexRf8.html2026-10-09T20:30:00-04:00

IB Chemistry Reactivity 3.3, electron sharing reactions: radicals and homolytic fission (part 1 of 5, for SL and HL). What a radical is, how homolytic fission makes two radicals, and why the reaction of a halogen needs UV light. Includes a six mark exam-style question solved step by step.

https://theibaxolotl.com/lessons/2d-arrays-in-java-rows-columns-hrUkOL5Vmpo.html2026-10-09T20:30:00-04:00

IB Computer Science B2.2, 2D arrays in Java: rows, columns and indexes (part 1 of 8, for SL and HL). What a 2D array is in Java, how to create one, and how to read and change one element. With a 5-mark exam question solved step by step.

https://theibaxolotl.com/lessons/exponent-laws-what-a-logarithm-is-SBOJhLgjKBE.html2026-10-09T13:30:00-04:00

IB Math AA 1.5 (Mathematics: Analysis and Approaches), exponents and logarithms: the laws of exponents and what a logarithm is (part 1 of 7, for SL and HL). The laws of exponents, what a logarithm is, and the two bases on your calculator: 10 and e. Includes a six mark Paper 1 style question solved step by step.

https://theibaxolotl.com/lessons/amino-acids-peptide-bonds-how-to-draw-them-YRXlB7PRp3U.html2026-10-06T13:30:00-04:00

IB Biology B1.2, proteins: amino acids and peptide bonds (part 1 of 7, for SL and HL). The four parts of every amino acid, how two amino acids join by condensation to form a dipeptide, and how a long chain becomes a polypeptide. Includes how to draw it for full marks.

https://theibaxolotl.com/lessons/protein-denaturation-heat-ph-explained-VZvpeqVSjAQ.html2026-10-06T13:30:00-04:00

IB Biology B1.2, proteins: essential amino acids, the variety of polypeptides and denaturation (part 2 of 7, for SL and HL). Why essential amino acids must come from food, why the number of possible polypeptides is enormous, and how heat and pH denature a protein.

https://theibaxolotl.com/lessons/alpha-helix-beta-sheet-protein-structure-iWNj0JsB6fM.html2026-10-06T13:30:00-04:00

IB Biology B1.2, proteins: R-groups, primary structure and secondary structure, the alpha helix and the beta-pleated sheet (part 3 of 7, higher level). The chemical types of R-group, why the sequence of amino acids decides the shape, and how the alpha helix and the beta-pleated sheet are held by hydrogen bonds in the backbone.

https://theibaxolotl.com/lessons/tertiary-quaternary-protein-structure-mBuW-7R_oZk.html2026-10-06T13:30:00-04:00

IB Biology B1.2, proteins: tertiary structure and quaternary structure (part 4 of 7, higher level). The four interactions between R-groups that hold tertiary structure, polar and non-polar amino acids in a folded protein, quaternary structure, and how the form of a protein fits its function (insulin, collagen, haemoglobin).

https://theibaxolotl.com/lessons/how-insulin-is-made-polypeptide-modification-vhMEYBP0MKI.html2026-10-06T13:30:00-04:00

IB Biology B1.2, proteins: how insulin is made, the modification of polypeptides and proteasomes (part 5 of 7, higher level). How a new polypeptide is modified before it can work, how pre-proinsulin becomes insulin in two stages, and how proteasomes recycle amino acids. Ends with the two guiding questions of the topic.