What Is IB Biology?
IB Biology is a Group 4 science subject in the IB Diploma Programme. It delves into living organisms, their interactions, and the biological processes that underpin life. The 2025 syllabus is structured around four core themes, explored across four levels of biological organization (molecules, cells, organisms, ecosystems), and emphasizes scientific inquiry and real-world connections.
Curriculum Structure (2025 Syllabus)
The course is defined by four major themes, each present in both Standard Level (SL) and Higher Level (HL):
- Theme A – Unity and Diversity:
Understanding how shared biochemical foundations support life’s variety and evolution. - Theme B – Form and Function:
Exploring how organism structures reflect their roles and survival. - Theme C – Interaction and Interdependence:
Examining systems through the lens of interactions and emergent properties. - Theme D – Continuity and Change:
Investigating mechanisms that maintain life balance and drive evolution.
These themes provide a conceptual framework that connects different aspects of biology across scales and contexts
Core Topics
All students at SL and HL study these essential topics:
- Cell Biology – cell structure, transport systems, origins of cells, viruses
- Molecular Biology – biomolecules, metabolism, DNA/RNA, photosynthesis, respiration
- Genetics – inheritance patterns, meiosis, genetic modification
- Ecology – ecosystem dynamics, energy flow, biodiversity
- Evolution and Biodiversity – mechanisms of evolution, classification
