Question

Given below are two statements about the oxygen dissociation curve.
Statement (I): The relationship between HbO\({}_{2}\) saturation and oxygen tension (ppO\({}_{2}\)) is called oxygen dissociation curve.
Statement (II): Oxygen dissociation curve shifts towards the right due to decrease in H\({}^{+}\) concentration and decrease in temperature.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

The curve shifts to the right with more H+, more CO2 and higher temperature, not with a fall in them.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
The oxygen dissociation curve is the sigmoid curve plotting percentage saturation of haemoglobin with oxygen against the partial pressure of oxygen.

Step 2: Statement (I)
This is the correct definition of the oxygen dissociation curve, so Statement (I) is correct.

Step 3: Statement (II)
The curve shifts to the right (lower affinity of haemoglobin, more oxygen released) when \(\text{H}^{+}\) concentration, \(\text{pCO}_{2}\) and temperature increase.
A decrease in \(\text{H}^{+}\) and temperature shifts the curve to the left, so Statement (II) is incorrect.

Final Answer:
Statement (I) is correct but Statement (II) is incorrect. \[ \boxed{\text{(C) }\text{Statement (I) is correct but Statement (II) is incorrect}} \]