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IB Biology HL community
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Biology HL chapters
40 topics · free- A1.1Water
- A1.2Nucleic acids
- A2.1Origins of cells
- A2.2Cell structure
- A2.3Viruses
- A3.1Diversity of organisms
- A3.2Classification and cladistics
- A4.1Evolution and speciation
- A4.2Conservation of biodiversity
- B1.1Carbohydrates and lipids
- B1.2Proteins
- B2.1Membranes and membrane transport
- B2.2Organelles and compartmentalization
- B2.3Cell specialization
- B3.1Gas exchange
- B3.2Transport
- B3.3Muscle and motility
- B4.1Adaptation to environment
- B4.2Ecological niches
- C1.1Enzymes and metabolism
- C1.2Cell respiration
- C1.3Photosynthesis
- C2.1Chemical signalling
- C2.2Neural signalling
- C3.1Integration of body systems
- C3.2Defence against infectious disease
- C4.1Populations and communities
- C4.2Transfers of energy and matter
- D1.1DNA replication
- D1.2Protein synthesis
- D1.3Mutation and gene editing
- D2.1Cell and nuclear division
- D2.2Gene expression
- D2.3Water potential
- D3.1Reproduction
- D3.2Inheritance
- D3.3Homeostasis
- D4.1Natural selection
- D4.2Stability and change
- D4.3Climate change
Papers in Biology HL
- HLPaper 1Practise under timed conditions, then mark against the band descriptors.
- HLPaper 2Drill the question style, then review the markbands to push into the top band.
- HLPaper 3Drill the question style, then review the markbands to push into the top band.
How IB marking differs
Unlike point-based A-Level mark schemes, IB uses markbands — examiners place your answer in a level band against descriptors. Knowing the band wording is how you turn a 5 into a 7.
Check your work
Upload a photo of your answer and get structured, criteria-based feedback on where the marks are.
Get feedback ->IB Biology HL — papers & markbands
Multiple choice (Paper 1), data and extended response (Paper 2) and the option/short-answer paper (Paper 3). Above are the papers you'll sit and how examiners award marks. Practise past papers, learn the markbands, then check your own answers for feedback.
Frequently asked questions
- What papers are in IB Biology HL?
- IB Biology at HL is assessed by Paper 1, Paper 2, Paper 3, plus internal assessment. Multiple choice (Paper 1), data and extended response (Paper 2) and the option/short-answer paper (Paper 3).
- How is IB Biology marked?
- IB uses markbands and assessment criteria rather than point-based A-Level marking codes — examiners place your response in a level band against descriptors. Our guides show what separates the top band from the middle on each paper.
- Where can I find IB Biology HL past papers?
- Browse every recent Biology HL exam series on our IB Biology past-papers page, organised by session and paper, with mark-scheme guidance for each.
- Is there a free IB Biology course?
- Yes — MarkScheme has a free topic-by-topic IB Biology course with worked examples, flashcards, and criterion practice marking on every syllabus point.
Best free IB Biology resources
Hand-picked, fully legal and free — official IB papers plus the best teacher-made notes and solutions.