What is G1 referred to as?

G1, or the first gap phase, is primarily referred to as a growth phase in the cell cycle. During G1, the cell increases in size, produces RNA, and synthesizes protein, effectively preparing for DNA replication. This phase is vital for cell growth and metabolism, as it ensures that the cell has the necessary resources and is ready to proceed to the next phase.

Additionally, G1 is also associated with a critical checkpoint known as the restriction point, where the cell assesses whether conditions are favorable for division. If conditions are not right, the cell may enter a resting state called G0. However, the primary identifying characteristic of G1 is its role in growth and preparation for DNA synthesis, as it lays the foundational work for the later phases of the cell cycle.