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

Ex Input:
You call the hard case that surrounds the soft parts of some animals the exoskeleton.

Ex Output:
What do you call the hard case that surrounds the soft parts of some animals?


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

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


Ex Input:
Sex cells are produced in both the male and female reproductive systems in humans.

Ex Output:
What are produced in both the male and female reproductive systems in humans?