Final answer:
The statement is true; endolymph in the inner ear has a high concentration of potassium and a low concentration of sodium, which is similar to intracellular fluid.
Step-by-step explanation:
The statement that endo-lymph (inner ear fluid) is characterized by low Na⁺ and high K⁺ concentration, similar to intracellular fluid, is True. The inner ear fluid, known as endolymph, indeed has a unique composition compared to most extracellular fluid (ECF). Typical ECF, such as blood plasma and interstitial fluid, has high concentrations of Na⁺ and Cl⁻ ions, whereas K⁺ is more concentrated inside cells. Endolymph is an exception to this rule; like intracellular fluid (ICF), it has a high concentration of K⁺ and low levels of Na⁺, which is crucial for the function of the sensory cells in the organ of Corti within the inner ear.