Neco Model Questions Vol1 2020 Biology Question 45

A high‑altitude mammal exhibits three physiological changes relative to its low‑land counterpart: (i) haemoglobin concentration rises from \(150\) g L\(^{-1}\) to \(200\) g L\(^{-1}\); (ii) resting ventilation rate increases from \(5\) L min\(^{-1}\) to \(8\) L min\(^{-1}\); (iii) muscle capillary density rises from \(2000\) capillaries mm\(^{-3}\) to \(3000\) capillaries mm\(^{-3}\). Assuming oxygen uptake (\(VO_{2}\)) is proportional to the product \(C_{Hb}\times V \times D\) (where \(C_{Hb}\) is haemoglobin concentration, \(V\) ventilation rate and \(D\) capillary density), which single adaptation, if introduced alone while the other two remain at low‑land values, would give the greatest percentage increase in \(VO_{2}\) compared with the low‑land baseline? State the adaptation and the percentage increase.