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

[EX Q]: The active transport of ions across the membrane causes an electrical gradient to build up across the plasma membrane.
[EX A]: The active transport of ions across the membrane causes an electrical gradient to build up across the what?

[EX Q]: Sodium chloride is an odorless white solid that is harmless unless consumed in large quantities.
[EX A]: What is an odorless white solid that is harmless unless consumed in large quantities?

[EX Q]: Does the stream-lined body featured on most fish increase or decrease water resistance?
[EX A]:
Does the stream-lined body featured on most fish increase or decrease water resistance?