IB Biology Syllabus Update - First Assessment 2025

The New IB Biology Curriculum

The IBDP has an exciting new science curriculum for first teaching in September 2023 and first assessment in May 2025. The four Options examined in Paper 3 have been scrapped and some of the content has been incorporated in the new curriculum.

The new DP Biology course has undergone a radical overhaul in approach and has been constructed to promote concept-based teaching and learning. Read about it in the Biology Subject Brief.

There are four overarching themes, each comprising of two concepts:

Theme A: Unity and diversity

Theme B: Form and function

Theme C: Interaction and interdependence

Theme D: Continuity and change

These themes are divided into four levels of biological organisation covering 40 topics and subtopics headed by guiding questions. Linking questions are used to facilitate connections between different parts of the course to promote a highly networked understanding of biology.

IB Biology Syllabus Outline from 2023

Study Skills in Biology

The skills and techniques students must experience through the course are encompassed within the tools: Experimental Techniques, Technology and Mathematics. These support the application and development of the inquiry process in the delivery of the biology course: Exploring & Designing, Collecting & Processing Data, and Concluding & Evaluating.

Source: ibo.org

What Will the New IB Biology Exams Look Like?

Students will have to take two external exams made up from the following components:

IB Biology SL Assessment Components 2025

IB Biology HL Assessment Components 2025

Comparing the 2014 syllabus with the 2023 syllabus 

• Options have been removed and some parts of the previous options are now integrated into the new syllabus. As a result, Paper 3 is no more. 

• However, it is worth noting, the IB did not just move all the option material into he core and AHL. It was a very select process looking at how a topic or subtopic now could blend in with one of the new core or AHL syllabus. 

• The syllabus is less content-heavy (about 5% less). 

• There is an emphasis on linking questions - teachers and students are encouraged to make links between topics.

• There are changes in the assessment - since there now is no Paper 3, they have had to revamp papers 1 and 2 slightly. 

• Paper 1 now has 2 parts- 1A is multiple choice and 1B consists of data-based questions, questions on lab skills, scientific methods, and more.

• Paper 2 is very similar to the previous paper 2, but slightly longer. For example, now it is 2 hours 30 minutes in HL, and 80 marks.

• There is still the same total number of hours students are sitting the exam, but it is now redistributed over 2 papers instead of 3.

• The 'Group 4 Project', is now called the 'Collaborative Science Project'.

• The 'Internal Assessment' is now the 'Scientific Investigation' and students can sometimes use data collected in group work on field trips (although each student's research question has to be different).

• There are now 4 criteria, each equally weighted at 6 marks each (for a total of 24 marks): research design, data analysis, conclusion, and evaluation.

• In terms of the syllabus roadmap, teachers can choose what sequence works for them. One of the inconvenient aspects of the roadmap version, is sometimes a topic or an idea will be introduced before that topic has been fully given in a future chapter, so sometimes it is better to jump ahead and then come back to the previous part of the roadmap. Therefore it is recommended not to completely teach it in order, although this depends on the teacher and what works for them. 

New Materials to Help You Study IB Biology

We are updating all our resources for the new IB course so that whether you are a student or a teacher, you can depend on them for high quality learning and revision - perfect for acing those exams!

In the meantime, browse our existing IB Biology revision resources.