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

Input: Consider Input: Phospholipids are the main component of the cell membrane.

Output: What is the main makeup of the cell membrane?


Input: Consider Input: Plasma membranes encloses and defines the borders of cells.

Output: What encloses and defines the borders of cells?


Input: Consider Input: Urea vertebrate animals metabolize ammonia what is the primary byproduct that is produced.


Output: When vertebrate animals metabolize ammonia what is the primary byproduct that is produced?