How to prepare for the USABO
Build the biology knowledge the Open Exam demands — from the right textbooks through timed past-paper practice. This page covers everything you need to prepare well.
USABO preparation hub
- USABO Past Papers (2003–2025)
- USABO Exams — Format & Syllabus
- USABO Prep Resources (you are here)
- USABO China Region
Scan the QR on the past-papers page to get the full free pack.
Recommended reading
These four texts cover the breadth and depth the Open Exam requires. Use them together: no single book covers everything equally well.
The standard starting point. Covers all seven syllabus areas with clear explanations and illustrations — use it to build breadth first.
Alberts is the authoritative reference for cell and molecular biology. Go deeper here once Campbell has given you the map.
Klug’s dedicated genetics text fills gaps left by Campbell — essential for the genetics and evolution questions that recur in the Open Exam each year.
Vander covers animal anatomy and physiology at the level the exam expects — use it alongside Campbell’s animal chapters for complete coverage.
A three-phase approach
Build core knowledge
Work through Campbell chapter by chapter, annotating as you go. Follow up with Alberts for cell biology and Klug for genetics. This foundation phase typically takes the most time — do not rush it.
Drill all 7 syllabus areas
The Open Exam draws from the full IBO syllabus. Make sure you have covered each area:
- Cell biology & molecular biology
- Genetics & evolution
- Plant anatomy & physiology
- Animal anatomy & physiology
- Animal behaviour (Ethology)
- Ecology
- Biosystematics
Work past papers under exam conditions
The exam is 50 questions in 50 minutes. Practise timed papers to build pace and identify gaps. Review every wrong answer against your textbooks rather than simply moving on.
The 2003–2025 Open Exam archive
The complete archive of USABO Open Exam papers from 2003 to 2025 is the single best practice resource available. Working through real papers under timed conditions shows you exactly what the exam demands — the question style, the level of depth, and the distribution of topics — in a way no textbook can replicate.
Past papers →Preparation questions
How early should I start preparing?
There is no single right answer, but the syllabus is broad. Most students benefit from beginning several months before the exam so they have time to work through the textbooks properly before moving to timed past-paper practice. See competition details for exam-date guidance.
Which book should I read first?
Start with Campbell Biology. It covers all seven syllabus areas and gives you the breadth you need before going deeper with Alberts (cell biology) or Klug (genetics). Vander’s physiology text is most useful once the Campbell chapters on animal physiology are done.
How many past papers should I do?
Do as many as time allows from the archive on the exams page. Each paper reinforces knowledge and builds exam pace. More recent papers are especially useful because the topic balance reflects current trends, but older papers cover the same core concepts and are equally valuable for practice.
Do I need a tutor or coaching programme?
Many students prepare successfully using the textbooks and past papers without formal coaching. A tutor or structured programme can be helpful if you find it difficult to work through the material independently or if you want structured feedback on your progress. What matters most is consistent, focused study across all seven areas.
Is the exam in English?
Yes. The Open Exam is in English. Reading your textbooks in English and doing all past-paper practice in English will help you build the scientific vocabulary the questions use. No translation is provided during the exam.
Preparation support from ASDAN
ASDAN runs the China region (BIOUS) and offers preparation support for students taking the Open Exam. If you have questions about study resources, exam logistics, or how to get started, you are welcome to contact the ASDAN team directly.
Registration and exam-date information is published each season on the registration page.
Contact us →Talk to a USABO advisor
Questions about preparation, registration, or the exam? Reach our advisors on WhatsApp.