Write a note on the `G_(0)` phase of cell cycle.

Explanation

`G_(0)` phase : Some cells in the adult animals exit `G_(1)` phase and enter an inactive phase called quiescent state or `G_(0)` phase of the cell cycle.
Cells in this stage remain metabolically active. But these cells do not exhibit cell division, unless called on to do so depending upon the requirement of an organism.
Therefore, they devide occasionally, as needed to replace cells that have been lost due to injury or cell death.