You will be given a definition of a task first, then some input of the task.
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

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