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

Input: Consider Input: If two populations do not mate and produce fertile offspring, separate species result.

Output: If two populations do not mate and produce fertile offspring, what results?


Input: Consider Input: Filter feeders called rotifers collect digestive and excretory wastes in cloacal bladder primitive organ.

Output: Filter feeders called rotifers collect digestive and excretory wastes in what primitive organ?


Input: Consider Input: Renewable energy sources emit fewer or no greenhouse gases.


Output: What type energy sources emit fewer or no greenhouse gases?