P50 is the partial pressure of oxygen at which haemoglobin is 50% saturated with oxygen. It is used as a measure of haemoglobin's affinity for oxygen. State the P50 for blood samples L and M.
With reference to Fig. 3.1, describe the ways in which the dissociation curve for person M is different from the dissociation curve for person L.
Explain the benefit of the position of the dissociation curve for people with sickle cell anaemia.
The partial pressure of oxygen in the lungs at sea level is about $13.5\,\text{kPa}$. At an altitude of $3000\,\text{metres}$ the partial pressure of oxygen in the lungs is about $7.5\,\text{kPa}$. When people move from sea level to high altitude they become adapted to the low partial pressure of oxygen. Describe and explain how humans adapt to the low partial pressure of oxygen at high altitude.
Vaccination is used to control the spread of diseases, such as measles. Explain why vaccination cannot be used to prevent sickle cell anaemia.