The answer is: to act as a ceremonial role within the Senate.
The phrase 'Pro Tempore' is a latin language with the meaning of 'for the time being'. President pro tempore of the senate only elected as a ceremonial role when the actual presiding officer of the senates is unable to attend the meeting/conference.
It can't be metaphase becasue the chromosones have appered, and it can't be prophase cause the chromosones have are being pulled. IT is anaphase cause the neclear membrane has not reappered