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IBScienceIBO

IB Biology HL

Higher Level IB Biology covers cells, molecular biology, genetics, ecology, evolution, and human physiology in depth, taught through the unifying themes of unity, diversity, form, function, interaction, and continuity.

Difficulty

Very Hard

Popularity

74%

Past questions

3

Study tips

5

Key Topics

CellsMolecular BiologyGenetics & InheritanceEcologyEvolution & BiodiversityHuman PhysiologyNucleic Acids (HL)Metabolism (HL)

Exam Format & Dates

When Offered

May & November, annually

Total Duration

Papers 1–3 ≈ 4h 30m + Internal Assessment

Scoring

1–7 scale (IB)

Pass Score

4 = passing | 6–7 = excellent

Administered by: International Baccalaureate OrganizationNext date: May 2026
SectionDurationContentWeight
Paper 1 — Multiple Choice + Data2 hours~40 MCQ + data analysis36%
Paper 2 — Extended Response2 hours 30 minutesShort + extended answers44%
Internal AssessmentCoursework (10 hours)1 independent investigation20%

Exam Breakdown & Insights

Paper 1 — Multiple Choice + Data36%
Paper 2 — Extended Response44%
Internal Assessment20%
5/5

Difficulty · Elite

74

Popularity score

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1 votes

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Study Tips

  1. 1

    Review required practicals and data-analysis skills — experimental questions appear on nearly every paper.

  2. 2

    Make concept maps connecting topics — modern exam questions frequently cross unit boundaries.

  3. 3

    Draw and label diagrams for every major process — reproducing them from memory is a powerful test of understanding.

  4. 4

    Past papers with mark schemes are the single best IB revision resource — learn exactly how marks are allocated.

  5. 5

    Do not neglect your Internal Assessment: it is a significant chunk of your grade that you control before exam day.

Past Exam Questions

MediumCells2023

Define Cells and state the key facts a student must know, using precise scientific terminology.

HardMolecular Biology2022

Explain the mechanism behind Molecular Biology: describe what happens and, crucially, why it happens. Include a labelled diagram where appropriate.

MediumGenetics & Inheritance2024

Design an experiment (or interpret given data) to investigate Genetics & Inheritance. Identify the variables, describe the method, and explain how you would analyse the results.

Common Mistakes to Avoid

  • Using vague everyday language where precise scientific terminology is required.

  • Ignoring units and significant figures in calculations.

  • Cramming content while neglecting experimental-design and data-analysis questions.

Official Resources

Free, official study material for IB Biology HL — always start with the source your exam board publishes.

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