During which phase of the cell cycle the cellular content of DNA is doubled -

There are two resting phases and two active phases in the cycle. Resting phases → G1 & G2 Active phases S-phase (synthetic phase) - As the name suggests, synthesis of new DNA takes place, i.e. doubling of DNA occurs. M-phase (mitotic phase) - Mitosis takes place and the daughter cells receive one copy of DNA. In this phase, cell number is doubled.