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

[Q]: Deep currents are caused by differences in density at the top and bottom of the ocean.
[A]: What is caused by differences in density at the top and bottom of the ocean?

[Q]: A theory is another name for a broad explanation that is supported by a great deal of evidence.
[A]: What is another name for a broad explanation that is supported by a great deal of evidence?

[Q]: The haploid gametophyte produces gametes through mitosis.
[A]:
By what process does the haploid gametophyte produce the gametes?