What is `G_(0)` (quiescent phase) of cell cycle?

Explanation

### Step-by-Step Solution:

1. **Definition of G0 Phase**: The G0 phase, also known as the quiescent phase, is a stage in the cell cycle where cells are in a state of inactivity or dormancy. This phase is distinct from the actively dividing phases of the cell cycle.

2. **Characteristics of G0 Phase**:
- Cells in the G0 phase are metabolically active, meaning they continue to carry out their normal functions and processes.
- However, they lose their ability to proliferate, which means they do not divide or replicate unless prompted by specific signals.

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