IB Biology HL Notes

Biology

Aimnova provides free IB Biology Higher Level revision notes for the first-exams-2025 syllabus, covering all four themes plus the HL-only extensions — extra depth in molecular biology, physiology, ecology and genetics. Each topic features detailed concept notes, labelled diagrams, worked examples, exam tips, flashcards, and practice questions with AI feedback.

IB Biology Higher Level extends the SL course with greater depth in every theme and a heavier load of detail — deeper enzyme and metabolic pathways, more physiology, population and community ecology, and the molecular basis of inheritance and gene expression. HL papers are longer and demand more rigorous explanation, data analysis, and evaluation than SL.

Use the theme-by-theme structure below to revise systematically and ensure no HL-only material is missed before Paper 1 (Section A multiple choice and Section B data analysis) and Paper 2 (short-answer and extended-response).

What's included

All 4 themes plus experimental and data skills, aligned to the first-exams-2025 syllabus
Concept notes with labelled diagrams of cells, systems, and processes
Worked examples and data-analysis technique for Paper 1 Section B
Spaced-repetition flashcards for definitions, processes, and command-term recall
IB-style practice questions with AI marking and feedback
Guidance for Paper 1 (Section A MCQ + Section B data) and Paper 2 (short + extended)
SL and HL coverage with level toggle
Free to access — no account required for notes

How to use Biology HL notes

1Start with a unit overview. Click any Theme heading to see every topic and the key biology it covers.
2Read micro-topic notes. Read one topic at a time and follow the concept, the labelled diagram, and the worked example.
3Test with flashcards. Use Biology flashcards to lock in definitions, processes, and command-term answers.
4Practise exam questions. Apply the method to IB-style questions and get AI feedback on where marks are won and lost.