Some cells in adult animals do not appear to exhibit division (e.g., heart cells) and enter an inactive stage called the quiescent stage ( G₀ ). Which specific phase of the standard cell cycle do these cells exit to enter the G₀ phase?

Step-by-step solution

According to NCERT, cells that do not divide further exit the G₁ phase to enter an inactive stage called the quiescent stage ( G₀ ) of the cell cycle. These cells remain metabolically active but no longer proliferate unless called on to do so depending on the requirement of the organism. Therefore, the correct exit point from the standard cell cycle is the G₁ phase. Answer: G₁ phase