Question

What would happen if DNA did not duplicate during interphase

Answer 1

 Sometimes a cell inaccurately duplicates its DNA, and the resulting cells are not identical.

Answer 2

I assume you are referring to DNA replication which takes place in the synthesis (S) phase of the cell cycle shortly before G2. If that doesn't happen, the cell will not proceed to G2 and eventually mitosis, thus division will not complete.
(mark as brainly)