In the cell cycle, the phases that precede (G1) and follow (G2) the synthesis (S) phase in which DNA is replicated; in the G1 phase, the cell doubles in size, and its enzymes, ribosomes, and other cytoplasmic molecules and structures increase in number; in the G2 phase, the replicated chromosomes begin to condense and the structures required for mitosis or meiosis are assembled.
