Final answer:
Cells in the Go phase spend most of their lives in a quiescent (inactive) stage. Some cells enter Go temporarily until an external signal triggers the onset of G1, while others, like mature cardiac muscle and nerve cells, remain in Go permanently.
Step-by-step explanation:
Cells in the Go phase spend most of their lives in a quiescent (inactive) stage that occurs when cells exit the cell cycle. Some cells enter Go temporarily until an external signal triggers the onset of G1. Other cells that never or rarely divide, such as mature cardiac muscle and nerve cells, remain in Go permanently. The Go phase is a resting phase where the cell has left the cycle and has stopped dividing. Non-dividing cells in multicellular eukaryotic organisms enter Go from G1. These cells may remain in Go for long periods of time, even indefinitely, such as with neurons. Cells that are completely differentiated may also enter Go.