Question

When does DNA replication occur in a cell?

Answer 1

DNA replication occurs in the S phase (The phase of DNA synthesis)

Step-by-step explanation:

This replication of DNA occurs during interphase in the S phase. (2nd phase in the process).

Answer 2

interphase
DNA replication occurs during the S-stage of interphase. DNA replication (DNA amplification) can also be performed in vitro (artificially, outside a cell).
Hope this helped.