Here's why:
* G1 (Gap 1) Phase: This is the first and longest phase of interphase. During G1, the cell grows significantly in size, synthesizes new proteins and organelles, and prepares for DNA replication.
* S (Synthesis) Phase: The cell replicates its DNA in this phase. While important, this is primarily focused on DNA duplication, not overall cell growth.
* G2 (Gap 2) Phase: Here, the cell continues to grow and prepares for mitosis. However, G2 is generally shorter than G1, with less emphasis on overall growth.
* Mitosis: The cell divides its nucleus and cytoplasm into two daughter cells. This is not a growth phase but a division phase.
Therefore, the majority of cell growth occurs in the G1 phase, where the cell accumulates the necessary materials and prepares for the subsequent stages of the cell cycle.
