Which of the following types of ions are most likely to cross the plasma membrane of a resting neuron?
A)K⁺
B)Na⁺
C)Ca⁺⁺
D)Cl⁻
E)Mg⁺⁺

Question

Quizplus · Accepted Answer

K⁺ and Cl⁻ ions are both permeable to the plasma membrane of a resting neuron. This is due to the presence of ion channels that are selectively permeable to these ions. Na⁺ and Ca⁺⁺ ions, on the other hand, cannot cross the plasma membrane of a resting neuron due to the presence of voltage-gated channels that are closed at rest. Mg⁺⁺ ions are also unlikely to cross the plasma membrane due to their larger size and charge.

Which of the Following Types of Ions Are Most Likely