CAIE A-Level Biology AS 8.2.4 Oxygen Dissociation Curve Questions
Interpret the oxygen dissociation curve and factors affecting haemoglobin affinity using evidence from each question and mark scheme.
- Syllabus
- 2028–2030
- Course
- Biology 9700
- Level
- AS
Exam points
- Interpret the oxygen dissociation curve and explain factors affecting haemoglobin affinity.
CAIE A-Level Biology AS 8.2.4 Oxygen Dissociation Curve Questions question 1
The graph shows how changes in oxygen concentration affect the percentage oxygen saturation of human haemoglobin and cat haemoglobin under normal physiological conditions. The partial pressure of carbon dioxide was kept constant at 5.0 kPa and the temperature was kept constant at .
Which conclusion is supported by the graph?
A
The affinity of cat haemoglobin for oxygen is greater than the affinity of human haemoglobin for oxygen.
B
At high partial pressures of oxygen, cat haemoglobin picks up oxygen more easily than human haemoglobin picks up oxygen.
C
At low partial pressures of oxygen, oxygen is released more easily from cat haemoglobin than from human haemoglobin.
D
The shift in the oxygen dissociation curve caused by the Bohr effect is larger for cat haemoglobin than for human haemoglobin.
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