Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

Question: The voltage of a voltaic cell can be determined by the reduction potentials of what? Answer: half reactions
The voltage of a voltaic cell can be determined by the reduction potentials of the half reactions.

Question: Magnetite crystals of different ages and on different continents pointed to different spots. the simplest explanation is that the continents have done what? Answer: moved
Magnetite crystals of different ages and on different continents pointed to different spots. The simplest explanation is that the continents have moved.

Question: What controls what moves inside and outside the cell? Answer: the plasma membrane
The plasma membrane controls what moves inside and outside the cell.