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

Example Input: Population is an important level of organization in ecology and the unit of microevolution.
Example Output: What is an important level of organization in ecology and the unit of microevolution?

Example Input: The active transport of ions across the membrane causes an electrical gradient to build up across the plasma membrane.
Example Output: The active transport of ions across the membrane causes an electrical gradient to build up across the what?

Example Input: Molecularity property is associated with the number of reactant molecules involved in an elementary step.
Example Output:
What property is associated with the number of reactant molecules involved in an elementary step?