Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
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Question: After fertilization, a zygote forms into two cells.

Answer: After fertilization, how many cells does a zygote form into?


Question: The energy stored in the organic molecules of food ultimately comes from the sun.

Answer: The energy stored in the organic molecules of food ultimately comes from where?


Question: Muscarinic receptors can cause both depolarization or hyperpolarization depending on the subtype.

Answer:
Muscarinic receptors can cause both depolarization or hyperpolarization depending on the what?