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

[EX Q]: Platelets blood component serves both structural and molecular functions in blood clotting.
[EX A]: What blood component serves both structural and molecular functions in blood clotting?

[EX Q]: The core of a star collapses during a supernova, forming a neutron star.
[EX A]: The core of a star collapses during what event, forming a neutron star?

[EX Q]: Theevolution by natural selection theory explains how populations of organisms can change over time.
[EX A]:
Which theory explains how populations of organisms can change over time?