Question

Given below are two statements:
Statement (I): In horses, there are two phases during inspiration and two phases during expiration.
Statement (II): The effect of carbon-dioxide and hydrogen ions on the ability of hemoglobin to yield or receive oxygen is referred as Bohr Effect.

• 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:

Remember the difference:
- Bohr Effect = Effect of \(CO_2\) and pH on Oxygen binding by hemoglobin.
- Haldane Effect = Effect of Oxygen on \(CO_2\) binding by hemoglobin.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
This problem addresses specialized respiratory physiology, comparing the unique respiratory mechanics of equines with the biochemically standardized Bohr effect of hemoglobin.

Step 2: Detailed Explanation:
Let us evaluate both statements:

Statement (I): Unlike most other domestic animals, the resting horse has a unique biphasic breathing pattern.
During resting inspiration, there is an initial passive phase followed by an active contraction of the diaphragm and external intercostal muscles.
Similarly, resting expiration is biphasic: it begins with passive elastic recoil of the lungs, followed by active contraction of the abdominal muscles (the "abdominal push") to force out the remaining air.
Thus, there are indeed two distinct phases during inspiration and two during expiration in horses. Statement (I) iscorrect.

Statement (II): TheBohr effect is a physiological phenomenon described by Christian Bohr.
It states that an increase in carbon dioxide concentration (\(\text{CO}_2\)) or hydrogen ion concentration (\(\text{H}^+\), which lowers pH) in the blood reduces hemoglobin's affinity for oxygen.
This causes hemoglobin to yield (release) its bound oxygen more easily in metabolically active, acidic tissues.
Conversely, in the lungs (where \(\text{CO}_2\) is exhaled and pH is higher), hemoglobin's oxygen affinity increases, allowing it to receive oxygen. Statement (II) iscorrect.
Since both Statement (I) and Statement (II) are correct, Option (A) is the correct choice.

Step 3: Final Answer:
The correct option is (A).