Question

Cell would normally proceed to mitosis without interruption

• A. once it has entered the $S$ phase
• B. once it has entered the $G_{2}$ phase
• C. at any time during cell division activity
• D. none of these

Answer 1

Answer: (A)

once it has entered the $S$ phase

Answer 2

The availability of mitogen and energy rich compounds decide whether $G_{1}$ phase will be arrested ($G_{0}$ phase) or undergo $S$-phase. This point is called check point or $G_{1}$ cydin or $G_{1}$ point. Once the check point of $G_{1}$-phase is crossed and cell has entered $S$-phase, cell cycle will go on further division till completion.