NEET2026BiologyChapterActual
The oxygen dissociation curve is a sigmoid curve that illustrates the relationship between the partial pressure of oxygen and the percentage saturation of haemoglobin. Under which of the following conditions will this curve shift to the right, promoting the release of oxygen to the tissues?
Options
- AHigh pCO ₂ and high H ⁺ concentration
- BLow H ⁺ concentration and low pCO ₂
- CLow pCO ₂ and low temperature
- DHigh pO ₂ and high pH
Correct answer
A. High pCO ₂ and high H ⁺ concentration
Step-by-step solution
The oxygen dissociation curve shifts to the right when the affinity of haemoglobin for oxygen decreases, which facilitates the unloading of oxygen to the tissues. This rightward shift is known as the Bohr effect. Factors that cause a right shift include: 1. High partial pressure of carbon dioxide ( pCO ₂ ) 2. High hydrogen ion concentration ( H ⁺ ), which corresponds to low pH 3. High temperature 4. High levels of 2,3-BPG Therefore, high pCO ₂ and high H ⁺ concentration will shift the curve to the right. Answer: Hi