IB Biology explores the living world at all levels — from molecular biology to ecosystems. You’ll develop an understanding of the structure and function of organisms, the interactions between species, and the processes that sustain life. The subject places strong emphasis on practical work, critical thinking, and the scientific method, preparing students for a broad range of scientific and health-related fields.
Experimental design and data analysis
Scientific writing and use of technical vocabulary
Critical thinking and application of biological principles to real-world issues
Collaboration and communication through group investigations
Ethical reasoning and global awareness of scientific impacts
IB Biology is offered at both Standard Level (SL) and Higher Level (HL). HL includes additional depth and content.
Core Topics (SL & HL):
There are 4 themes:
Unity and Diversity
Form and Function
Interaction and Interdependence
Continuity and Change
For each theme, there are 4 levels of organisation:
Molecules
Cells
Organisms
Ecosystems
Over the two years, students will be studying the following units:
Biomolecules
Cells
Metabolism
Genetics
Equilibrium
Body Systems and Plant Systems
Biodiversity
Nutrition
Ecosystems
There are HL content in most topics
The HL only units are:
Origins of cells
Viruses
Classification and cladistics
Muscle and Motility
Chemical signalling
Gene expression
Practical and Investigative Work:
Internal Assessment (IA): An individual investigation designed and carried out by the student
Group 4 Project: A collaborative interdisciplinary science project
Internal Assessment (IA)
Same for both HL and SL
Individual Investigation (20%)
You’ll design and conduct your own biological investigation and submit a detailed report (approximately 6–12 pages). This task assesses your experimental skills, data analysis, and understanding of the scientific process.
External Assessment
For Higher Level (HL):
Paper 1 (2 hours) = 36%
Paper 1A (40 marks): 40 questions on the core topics only
Paper 1B (35 marks): 4 data-based questions related to experimental work and the syllabus
Paper 1A and 1B are completed together without interruptions
Paper 2 (2 hours 30 minutes) = 44%
Section A (48 marks): One data-based question and short answer questions
Section B (32 marks): Extended response questions - two of three extended-response questions to be attempted by students.
For Standard Level (SL):
Paper 1 (1 hour 30 minutes) = 36%
Paper 1A (30 marks): 30 questions both SL and HL content
Paper 1B (25 marks): 4 data-based questions related to experimental work and the syllabus
Paper 1A and 1B are completed together without interruptions
Paper 2 (1 hour 30 minutes) = 44%
Section A (34 marks): One data-based question and short answer questions
Section B (16 marks): Extended response questions - one of two extended-response questions to be attempted by students.
IB Biology is an excellent foundation for:
Tertiary Courses: Medicine, Dentistry, Nursing, Biomedical Science, Environmental Science, Genetics, Agriculture, Biotechnology
Careers: Doctor, Research Scientist, Ecologist, Forensic Scientist, Genetic Counsellor, Conservationist, Biotechnologist, Public Health Analyst
It is particularly important for students considering health, life sciences, or environmental fields at university.