Question

When does a cell make copies of its DNA when preparing to divide?

Answer 1

The cell replicates, or makes a copy of, its DNA during the "S" phase of the cell cycle, which stands for "Synthesis."

Explanation:

As you can see here, the "S" phase is part of interphase, which is the period of the cell cycle when the nucleus is not undergoing division. Synthesis occurs after the "G1" phase but before the "G2" phase.