IB Biology HL 3.1.12 Bohr Shift Question Bank
Practise IB Biology HL 3.1.12 by interpreting oxygen dissociation curves and explaining how carbon dioxide and lower pH promote oxygen unloading.
- Syllabus
- First assessment 2025
- Course
- Biology HL
- Level
- HL
Practise IB Biology HL 3.1.12 by interpreting oxygen dissociation curves and explaining how carbon dioxide and lower pH promote oxygen unloading.
The graph shows the oxygen dissociation curve for adult hemoglobin.

Using the graph, draw a line to show how the oxygen dissociation curve changes with the Bohr shift.
partial pressure of oxygen

Explain the role of the Bohr shift during vigorous exercise.
a. more CO2 is produced which lowers the pH of the blood;
b. hemoglobin releases more oxygen (at lower pH ) for same partial pressure of oxygen;
c. more oxygen is available to respiring tissues;