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

Input: Consider Input: The active transport of ions across the membrane causes an electrical gradient to build up across the plasma membrane.

Output: The active transport of ions across the membrane causes an electrical gradient to build up across the what?


Input: Consider Input: Absorption is the process by which the substances you consume are taken up by the blood.

Output: What is the process by which the substances you consume are taken up by the blood?


Input: Consider Input: If a chemical reaction such as photosynthesis begins with 6 atoms of carbon (c), 6 atoms of carbon many atoms of carbon (c) should be in the products.


Output: If a chemical reaction such as photosynthesis begins with 6 atoms of carbon (C), how many atoms of carbon (C) should be in the products?