(a)[3]
Explain what causes oxyhaemoglobin to dissociate readily in actively respiring tissues.
(b)[3]
When people go to high altitudes, more red blood cells are produced. Explain why red blood cell production increases when people move to higher altitudes.
(c(i))[3]
Explain what transcription means.
(c(ii))[3]
Describe how a mutated version of the EPAS1 gene can bring about a change in the transcription factor protein produced.
(c(iii))[2]
Some transcription factors may prevent transcription. Suggest two ways in which they may do this.