Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[EX Q]: Sodium-potassium pumps help nerve cells establish a voltage across their plasma membranes.
[EX A]: Sodium-potassium pumps help nerve cells establish a voltage across their what?

[EX Q]: Environmental changes is most responsible for the extinction of most species of plants and animals that have lived on earth.
[EX A]: What process is most responsible for the extinction of most species of plants and animals that have lived on Earth?

[EX Q]: Inherited behavior is genetically passed on from parents to offspring statement explains why ducklings follow their mother when swimming across a pond.
[EX A]:
Which statement explains why ducklings follow their mother when swimming across a pond?