G1 Phase

In the G1 phase, the cell performs its normal physiological functions. It produces proteins, nucleic acids (RNA) and other substances. Cells that re-enter the cell division cycle need these substances for later cell building and cells that are intended for specific functions in a tissue or organ differentiate in the G1 phase. The G1 phase can last a few days, but also years. The latter, for example, in the case of the human egg cell, which can be in the G1 phase for decades.