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

Example Input: In prokaryotes, a(n) genome is composed of a single, double-stranded dna molecule in the form of a loop or circle.
Example Output: In prokaryotes, what is composed of a single, double-stranded dna molecule in the form of a loop or circle?

Example Input: There are three quarks in each proton and neutron.
Example Output: How many quarks are in each proton and neutron?

Example Input: Copper oxide substance is created when a copper turns from reddish brown to greenish brown.
Example Output:
What substance is created when a copper turns from reddish brown to greenish brown?