Given a scientific question, generate a correct answer to it.

Input: Consider Input: The cytoplasm is all the contents of the cell inside the cell membrane, with the exception of what?

Output: nucleus

Input: Consider Input: What type of experiment involves two identical experiments carried out side-by-side, with and without an independent variable?

Output: controlled experiment

Input: Consider Input: In which period of the periodic table is nickel found?
Output: fourth period