Final answer:
The G1 Phase is the stage in the cell cycle where the cell grows, performs metabolic functions, and prepares for division, but does not divide.
Step-by-step explanation:
The significant stage of the cell cycle in which the cell is growing, metabolizing, and maintaining itself and not dividing is the G1 Phase. The G1 phase, also known as the first gap, or growth phase, is a period where the cell increases in size and prepares the necessary components for DNA replication. It engages in rapid growth and performs routine metabolic processes. Proteins essential for DNA replication are synthesized during this time. If a cell is not dividing, it may enter a resting phase known as the Go phase. After the G1 phase, the cell then enters the S phase (synthesis phase), where it replicates its DNA, followed by the G2 phase where it makes final preparations for cell division. The interphase includes the G1, S, and G2 phases, where the cell is primarily focused on growth and preparation for division, which occurs during the M phase.