What is the shape of oxygen dissociation curve of haemoglobin?

Explanation

To answer the question about the shape of the oxygen dissociation curve of hemoglobin, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Oxygen Dissociation Curve**: The oxygen dissociation curve represents the relationship between the partial pressure of oxygen (pO2) and the saturation of hemoglobin with oxygen.

2. **Axes of the Curve**: The vertical axis of the curve shows the percentage saturation of hemoglobin with oxygen, while the horizontal axis represents the partial pressure of oxygen.

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