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

Example Input: A skeleton that consists of hard, mineralized structures located within the soft tissue of organisms is called endoskeleton.
Example Output: A skeleton that consists of hard, mineralized structures located within the soft tissue of organisms is called what?

Example Input: Transient pseudopodia are temporary feet that protists have called.
Example Output: What are temporary feet that protists have called?

Example Input: Gastro-esophageal sphincter sphincter is located at the stomach end of the esophagus and opens to allow the bolus to enter the stomach.
Example Output:
Which sphincter is located at the stomach end of the esophagus and opens to allow the bolus to enter the stomach?