The answer would be Variation that decrease reproductive success are mote likely to be passed on. It wi be the second option.
I think it is the second one I'm in bio right now and we just finished the energetics unit.
It’s an organ that is part of the circulatory system
The most basic function of the cell cycle is to duplicate accurately the vast amount of DNA in the chromosomes and then segregate the copies precisely into two genetically identical daughter cells.