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

Q: Sodium-potassium pumps help nerve cells establish a voltage across their plasma membranes.

A: Sodium-potassium pumps help nerve cells establish a voltage across their what?
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Q: Insulin is made up of two polypeptide chains.

A: Insulin is made up of how many polypeptide chains?
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Q: You call cellular respiration that does not need oxygen to proceed anaerobic respiration.

A:
What do you call cellular respiration that does not need oxygen to proceed?
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