Question

Which from following statements regarding biological importance of elements is NOT true?

• A. \(\text{Ca}^{2+}\) ions are required for contraction and stretching of muscles.
• B. \(\text{Mg}^{2+}\) ions are important for breaking of glucose and fats in protein synthesis.
• C. \(\text{K}^{+}\) ions are most abundant in extra cellular fluid.
• D. \(\text{Na}^{+}\) ions regulate water flow across the membrane.

Hint:

Sodium is the main extracellular cation and potassium is the main intracellular cation.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Biological roles: calcium ions for muscle contraction, magnesium ions as enzyme cofactors in glucose and fat breakdown, sodium ions for water balance and nerve signals, potassium ions inside cells.

Step 2: Check each statement
Statements (A), (B) and (D) match these roles and are true.

Step 3: Find the false statement
\(\text{K}^{+}\) is the most abundant cation in intracellular fluid. In extracellular fluid, \(\text{Na}^{+}\) is the most abundant. So statement (C) is not true.

Final Answer:
The statement that K+ is most abundant in extracellular fluid is not true. \[ \boxed{\text{(C) }\text{K}^{+}\text{ ions are most abundant in extra cellular fluid.}} \]