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Question #46310

Difficulty: 8/10 | 🟢 Free

The Question

A patient is diagnosed with a severe impairment of the tubular secretion mechanism in the nephrons, leading to an inability to excrete $H^+$ ions into the filtrate. Which of the following accurately describes the secondary physiological impact of this condition on respiratory gas transport?

Options

A.
The systemic accumulation of $H^+$ ions causes a leftward shift of the oxygen-hemoglobin dissociation curve, increasing $O_2$ affinity.
B.
The resulting metabolic alkalosis stabilizes the oxygen-hemoglobin complex, shifting the dissociation curve to the left.
C.
The increased $H^+$ concentration shifts the oxygen-hemoglobin dissociation curve to the right, decreasing the affinity of hemoglobin for $O_2$ .
D.
The failure to excrete $H^+$ ions directly decreases systemic $pCO_2$ levels, shifting the dissociation curve to the right to facilitate $O_2$ unloading.

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Regulatory_Failure

Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.

Concepts Behind This Question

Carbonic_Anhydrase|Tubular_Secretions|Hb_Affinity

Why This Question Is Tricky

Common Mistakes

Conceptual Pivot: This question requires the synthesis of two distinct NCERT chapters ('Excretory Products and their Elimination' and 'Breathing and Exchange of Gases').

Students must first connect renal tubular secretion failure to systemic acidosis (high $H^+$ ), and then apply the Bohr effect to determine the direction of the curve shift.

A common misconception is confusing the direction of the shift with its functional outcome (Right shift = Decreased affinity = Increased unloading).

Quick Facts About This Question

Question Information

Subject	Biology
Chapter	Breathing and Exchange of Gases - Class 11
Concept	Oxygen-Hemoglobin Dissociation Curve
Difficulty	8
Cognitive Load	5
Target Solve Time	120 sec
Access	Free