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

[Q]: Pangaea began breaking apart 250 million years ago.
[A]: How many millions of years ago did pangaea begin breaking apart?


[Q]: Stirring, surface area, and temperature affect the rate at solute dissolves what occurs.
[A]: Stirring, surface area, and temperature affect the rate at which what occurs?


[Q]: The axis of the plant has a root end and a shoot end.
[A]:
What part of the plant has a root end and a shoot end?