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

Example Input: A bow wake is created when the wave source moves faster than the wave propagation speed.
Example Output: What is created when the wave source moves faster than the wave propagation speed?

Example Input: Virtually all aquatic organisms depend directly or indirectly on protists for food.
Example Output: Virtually all aquatic organisms depend directly or indirectly on what for food?

Example Input: The discovery of ribozymes nullified the idea that all biological catalysts are proteins.
Example Output:
What nullified the idea that all biological catalysts are proteins?