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

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

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: Mars is the fourth planet from the sun.
Example Output:
Which is the fourth planet from the sun?