IB Biology SL Notes

Aimnova offers free IB Biology SL revision notes for the first-exams-2025 syllabus, covering all four themes from Unity and Diversity to Continuity and Change. Each topic includes clear concept explanations, labelled diagrams, worked examples, spaced-repetition flashcards, and IB-style practice questions with AI feedback — no sign-up required to read the notes.

IB Biology SL builds a connected understanding of life across four themes: Unity and Diversity (molecules, cells, viruses, classification and evolution); Form and Function (the relationship between structure and function from molecules to organisms); Interaction and Interdependence (cell signalling, homeostasis, ecosystems and the carbon cycle); and Continuity and Change (DNA replication, inheritance, gene expression and natural selection). Every topic links the biology to the data-handling and experimental skills examiners expect you to apply.

These notes are organised theme-by-theme according to the official IB syllabus, so you can revise systematically for Paper 1 (Section A multiple choice plus Section B data-based questions) and Paper 2 (short-answer and extended-response). SL students sit no Paper 3 and no options, so the focus stays on mastering the core themes and the experimental and data skills woven through them.