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

Plant nutrition is the study of the chemical elements necessary for plant growth.
What is the study of the chemical elements necessary for plant growth called?

Sodium-potassium pumps help nerve cells establish a voltage across their plasma membranes.
Sodium-potassium pumps help nerve cells establish a voltage across their what?

The term amines is used to describe molecules that contain carbon-nitrogen bonds.
What term is used to describe molecules that contain carbon-nitrogen bonds?