Final answer:
The cell cycle phase in which the cell is not involved in cell division and carries out normal functions is the G0 phase, a quiescent period where cells are inactive with respect to the division cycle.
Step-by-step explanation:
The phase of the cell cycle in which the cell is carrying out its normal activity and is not directly involved in cell division is known as the G0 phase. This is a phase where cells are in a state of dormancy and they are not actively preparing to divide. Cells that enter the G0 phase may do so temporarily until they are triggered to enter the G1 phase or they may remain in the G0 phase permanently, especially cells like mature cardiac muscle and nerve cells, which rarely or never divide. On the other hand, during the G1 phase, a cell grows, carries out all normal metabolic functions, and prepares for DNA replication, which occurs in the S phase. The S phase is followed by the G2 phase, where further growth and protein synthesis occur before moving into the mitotic phase of cell division.