The Electrochemical Gradient of a Given Ion Determines the Movement

question 7

Multiple Choice

The electrochemical gradient of a given ion determines the movement of that ion across a cell membrane.Based on your knowledge of the normal intra- and extracellular concentrations of Na⁺ and K⁺ ions across a resting membrane, what would you expect to happen when both Na⁺ and K⁺ voltage-gated channels were opened in response to an action potential?

• A) Na⁺ and K⁺ would both move out of the cell.
• B) Na⁺ would move into the cell, whereas K⁺ would move out of the cell.
• C) Na⁺ would move out of the cell, whereas K⁺ would move into the cell.
• D) Na⁺ and K⁺ would both move into the cell.
• E) Na⁺ would move out of the cell but K⁺ flow would cease.

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Definitions:

Variable Costing

An accounting method that assigns only variable production costs to products, treating fixed costs as period costs.

Absorption Costing

An accounting method that includes all manufacturing costs (fixed and variable) in the cost of a product.

Operating Income

Income generated from regular business operations, excluding deductions of interest and taxes.

Variable Costing

A costing method that includes only variable production costs (materials, labor, and overhead) in product costs, treating fixed costs as period costs.