Pearson Edexcel International Advanced Level Biology (YBI11)
Explore biological processes and applications through six units combining scientific knowledge and practical reasoning.
Specification Issue 2, February 2021
Course structure and assessment routes
- IAS Biology XBI11: Units 1–3. IAL Biology YBI11: all six units. Units may be assessed in stages or together at the end of the course.
Main syllabus content
- Molecules, diet, transport and health
- Cells, development, biodiversity and conservation
- Energy, environment, microbiology and immunity
- Respiration, internal environment, coordination and gene technology
- Practical skills I and II
Use Syllabus for the topic checklist. Where the qualification offers options, follow your chosen route rather than treating every option as compulsory.
YBI11 assessment structure
Use the route above to identify which components you take. Marks below are raw marks; the stated weightings determine their contribution to the award.
WBI11/01
Unit 1: Molecules, Diet, Transport and Health
- Duration
- 1 hour 30 minutes
- Marks
- 80
- Weighting
- 40% IAS / 20% IAL
WBI12/01
Unit 2: Cells, Development, Biodiversity and Conservation
- Duration
- 1 hour 30 minutes
- Marks
- 80
- Weighting
- 40% IAS / 20% IAL
WBI13/01
Unit 3: Practical Skills in Biology I
- Duration
- 1 hour 20 minutes
- Marks
- 50
- Weighting
- 20% IAS / 10% IAL
WBI14/01
Unit 4: Energy, Environment, Microbiology and Immunity
- Duration
- 1 hour 45 minutes
- Marks
- 90
- Weighting
- 20% IAL
WBI15/01
Unit 5: Respiration, Internal Environment, Coordination and Gene Technology
- Duration
- 1 hour 45 minutes
- Marks
- 90
- Weighting
- 20% IAL
WBI16/01
Unit 6: Practical Skills in Biology II
- Duration
- 1 hour 20 minutes
- Marks
- 50
- Weighting
- 10% IAL
Key assessment information
- All units are externally assessed written exams; practical investigations still form part of learning. Calculators are permitted. Unit 5 includes a pre-released scientific article. At least 10% of qualification marks assess mathematics at Level 2 or above.
Official sources and verification
Checked 2026-09-04 against the official YBI11 syllabus/specification (PDF). Specification Issue 2, February 2021.
Source PDF pages: 12, 13, 14, 15, 16. PDF page positions may differ from printed page numbers.
IGCSEfy is an independent study aid. Check the full official document and your exam-paper instructions, especially exam-year options, equipment and centre arrangements. Older archive papers may follow an earlier syllabus.