Question

Match List-I with List-II:

Choose the correct answer from the options given below:

• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (I), (B) - (III), (C) - (II), (D) - (IV)
• (A) - (I), (B) - (II), (C) - (IV), (D) - (III)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)

Hint:

Extracellular fluid is always high in \(\text{Na}^+\) (\(\approx 140 \text{ mmol/L}\)) and \(\text{Cl}^-\) (\(\approx 100 \text{ mmol/L}\)) but very low in \(\text{K}^+\) (\(\approx 4 \text{ mmol/L}\)).
Intracellular fluid shows the reverse trend.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Eukaryotic organisms maintain strict homeostasis of ion concentrations within extracellular and intracellular fluids to ensure proper physiological function.

Step 2: Detailed Explanation:
The typical concentrations of key electrolytes in human extracellular fluid (plasma) are:
- Sodium, \(\text{Na}^+\) (A): The major extracellular cation, maintained at a high level of approximately 140 mmol/L (I) (normal range: 135--145 mmol/L).
- Potassium, \(\text{K}^+\) (B): The major intracellular cation, kept very low in extracellular fluids at approximately 4 mmol/L (II) (normal range: 3.5--5.0 mmol/L) to prevent cardiac arrhythmias.
- Chloride, \(\text{Cl}^-\) (C): The primary extracellular anion, maintained around 100 mmol/L (III) (normal range: 98--106 mmol/L).
- Magnesium, \(\text{Mg}^{2+}\) (D): An essential divalent intracellular cation with low extracellular presence of approximately 1.5 mmol/L (IV).

Step 3: Final Answer:
The correct matching sequence is (A) - (I), (B) - (II), (C) - (III), (D) - (IV), corresponding to option (A).