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

[EX Q]: How much is involved in the reaction does the coefficient in front of an element in a formula indicate.
[EX A]: What does the coefficient in front of an element in a formula indicate?

[EX Q]: Negative growth rate results when birth rates fall even lower than death rates.
[EX A]: What results when birth rates fall even lower than death rates?

[EX Q]: The adult cells that form the butterfly begin growing in embryo developmental stage.
[EX A]:
The adult cells that form the butterfly begin growing in what developmental stage?