Which Answer Explains Why Na+ Ions Enter the Cell When

question 48

Multiple Choice

Which answer explains why Na+ ions enter the cell when voltage-gated Na+ channels are opened in neurons?

• A) the Na+ concentration is much lower outside the cell than it is inside the cell
• B) the Na+ ions are actively transported by the sodium-potassium pump into the cell
• C) the Na+ concentration is much higher outside the cell than it is inside, and the Na+ ions are attracted to the negatively charged interior
• D) the Na+ concentration is much higher outside the cell than it is inside, and the Na+ ions are actively transported by the sodium-potassium pump into the cell

---

Definitions:

Natural Disturbance

An event caused by non-human forces that significantly alters an ecosystem's structure or function.

Lightning Strike

A natural electrical discharge of very short duration and high voltage between a cloud and the ground or within a cloud.

Forest Fire

An uncontrolled fire that occurs in the wilderness, often in wooded areas, which can have both natural and human causes.

Tolerance

The capacity of an organism to endure exposure to a particular substance or environmental condition without adverse effects.