The $S-$phase of the cell cycle is characterized by

Which of the following is $NOT$ true for the $S$ phase?

Which of the following is applicable to the $G_1$ phase of the cell cycle?

If a dividing cell is placed in a medium containing radioactive thymidine,the radioactivity will first be observed in:

Which of the following is true for the $G_0$ phase?
$I.$ It is a quiescent stage.
$II.$ The cell cycle is arrested in this stage.
$III.$ $G_0$ cells do not grow or proliferate,but are metabolically active.
$IV.$ $G_0$ cells divide in response to stimuli.

If the initial amount of $DNA$ in a cell is $2C$,in which phase of the cell cycle will its amount become $4C$?