Question

Once human nerve cells become mature, they normally exit the cell cycle and remain in:

a) G0 phase
b) G1 phase
c) S phase
d) G2 phase

Answer 1

Mature human nerve cells exit the cell cycle and remain in the G0 phase, which is a permanent and non-dividing state.

Step-by-step explanation:

Once human nerve cells become mature, they normally exit the cell cycle and remain in the G0 phase. This phase is also known as the quiescent or resting stage. Unlike the G1, S, or G2 phases, where the cell is actively preparing to divide, cells in the G0 phase are not preparing for cell division. Mature nerve cells enter this phase permanently and do not divide again.

Cells in Go phase are not actively preparing to divide. Some cells enter Go temporarily until an external signal triggers the onset of G1. Other cells, such as mature cardiac muscle and nerve cells, remain in Go permanently.