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: Insulin is made up of two polypeptide chains.

Answer: Insulin is made up of how many polypeptide chains?


Question: Fractional crystallization is the separation of compounds on the basis of their solubilities in a given solvent.

Answer: What is the separation of compounds on the basis of their solubilities in a given solvent?


Question: Synapse is the term for a connection between a neuron and its target cell.

Answer:
What is the term for a connection between a neuron and its target cell?