Question

why second growth phase is called preparatory phase​

Answer 1

In mitosis, interphase can be further split into three sub-phases: the first is known as { G }_{ 1 }, for first gap or first growth; the second is known as the S phase, for synthesis

Answer 2

the G2 phase is second gap phase during which the cell continues to grow and make the nessecary preparation for mitosis . this is the region behind this.