How Many IB Biology Papers Are There?

Doing IB Biology revision and wondering exactly how many exam papers you'll be facing? With recent changes to the IB Biology syllabus, the exam structure has been updated. It's crucial you understand what you're working towards.

Whether you're taking Standard Level or Higher Level Biology, clarity on the paper structure helps you plan your revision time. Hopefully this will reduce your exam anxiety too. 

This guide breaks down exactly how many papers you'll sit. I'll go into what content each covers, and how they contribute to your final grade. By the end, you'll have a complete picture of your IB Biology assessment structure.

Key Takeaways

• IB Biology now has 2 main exam papers as of the 2025 syllabus update. Each is divided into sections A and B with different question types.

• Paper 1 combines multiple-choice questions (1A) with data-based questions (1B). Paper 2 includes data analysis (2A) and extended response questions (2B).

• The Internal Assessment remains a separate component. It's worth 20% of your final grade, alongside the two external exam papers.

• Both SL and HL students take the same paper structure. HL papers are longer, with additional content and more challenging questions.

Overview of the IB Biology Exam Format

How many IB Biology papers are there? Assessment consists of two main external exam papers (opens in a new tab) plus an Internal Assessment. This is following significant changes introduced with the 2025 syllabus update. We explain more in our article about the 2025 IB Biology syllabus update.

• Paper 1 is divided into two sections. Paper 1A contains multiple-choice questions. Paper 1B focuses on data-based questions related to practical work and syllabus content.

• Paper 2 also splits into two parts. Paper 2A includes data-based questions from unfamiliar contexts and short-answer questions. Paper 2B contains extended-response questions.

• The Internal Assessment (IA) runs alongside your course. It contributes 20% to your final grade. This involves designing and conducting your own scientific investigation.

This structure applies to both Standard Level and Higher Level students. Though, HL papers are longer and include additional content not covered at SL. Read more about course content in our article on IB Biology and our article comparing SL and HL IB Biology.

IB Biology Paper 1

• For Sl Students, Paper 1 is 1 hour and 30 minutes

• For HL students, Paper 1 is 2 hours 

Paper 1A: Multiple-choice questions

Paper 1A consists of multiple-choice questions. It covers both Standard Level content and Higher Level material.

For SL students, the paper tests core syllabus content across all themes. Questions range from straightforward factual recall to application of biological concepts.

HL students have additional questions covering Higher Level content that SL students don't study.

There's no penalty for incorrect answers. You should attempt every question even if you're unsure.

Paper 1B: Data-based questions

Paper 1B contains 4 data-based questions. It focuses on experimental work, scientific methods, and practical skills alongside IB syllabus content.

These questions test your ability to analyse experimental data, interpret graphs and tables, suggest improvements to experimental design, and evaluate conclusions.

HL students complete more complex data analysis tasks.

The questions often present unfamiliar contexts. They require you to apply biological knowledge to new situations, rather than simply recalling facts.

IB Biology Paper 2

• For SL Students, Paper 2 is 1 hour and 30 minutes

• For HL students, Paper 2 is 2 hours and 30 minutes

Paper 2A: Data-based questions

Paper 2A presents data-based questions from unfamiliar contexts. These challenge you to apply biological principles to scenarios you haven't seen before.

These questions often involve real scientific research, current biological discoveries, or applications of biology in medicine, agriculture, or environmental science.

You'll need to interpret complex data sets, suggest explanations for patterns, and make connections between different biological concepts.

Paper 2B: Extended-response questions

Paper 2B tests your ability to write detailed, structured answers about biological concepts and processes.

These questions require you to explain mechanisms, discuss processes, evaluate statements, and demonstrate understanding of how different biological systems interact.

Strong answers show clear scientific reasoning, use appropriate biological terminology, and make connections between different areas of the syllabus.

The extended responses separate students who truly understand biology from those who just memorise facts.

Paper Weightings for SL Biology vs HL Biology

Despite different paper lengths, the weightings for each paper (opens in a new tab) are the same for SL and HL. 

These weightings show that students should focus heavily on Paper 2 preparation, as it contributes 44% of their external assessment marks.

Explore our revision resources for SL IB Biology and resources for HL IB Biology. 

How Does the Internal Assessment Fit In?

The Internal Assessment involves designing, conducting, and analysing your own scientific investigation over the course of your IB Biology program.

Your teacher assesses your IA. They use criteria including personal engagement, exploration, analysis, evaluation, and communication skills.

The IA contributes 20% to your final grade. Unlike exam papers, you have months to work on your IA, allowing you to demonstrate skills that can't be tested in timed conditions.

Balance your revision time to include IA improvement alongside exam preparation. This is especially key if your current IA grade is below your target level.

Strong IA performance can significantly boost your overall Biology grade. It can also compensate for weaker exam performance.

Frequently Asked Questions

Are the IB Biology exam papers the same for SL and HL students?

The papers have the same structure and question types. HL papers are longer and include additional content not covered at Standard Level. HL students face more challenging questions and need deeper understanding of biological concepts. This is particularly the case in Paper 2 extended responses.

Which paper is the hardest?

Most students find Paper 2 most challenging, due to its extended response questions requiring detailed explanations and complex data analysis. However, difficulty varies by individual. Some students struggle more with Paper 1's time pressure and data-based questions.

Can I retake one paper if I do badly?

No, IB Biology is assessed as a complete qualification. If you retake the subject, you must sit all exam components again - you cannot retake individual papers. This makes thorough preparation across all papers essential for your first attempt.

Final Thoughts on IB Biology Papers

IB Biology now consists of two comprehensive exam papers as of 2025. Each tests different aspects of the syllabus through varied question formats.

Success requires both factual recall and analytical thinking. Use past papers and mark schemes to familiarise yourself with examiner expectations and question styles.

Remember that your Internal Assessment contributes significantly to your final grade. Don't neglect this component while focusing on exam preparation. Balance your time across all assessed elements for the best possible outcome.

The key to IB Biology success lies in understanding what each paper tests and preparing accordingly. With clear goals and focused revision, you can approach your exams with confidence and achieve your target grade.

References

• IB Biology Subject brief  (opens in a new tab)

• IB Biology Course Update (opens in a new tab)