Answer: DNA replication
DNA replication occurs in the nucleus (eukaryote cells). DNA replication occurs in the interphase when the cell is growing, its carrying processes and its replication it’s DNA 
Once the cell is replication it does not divide so both theses process are not carried out together .Helicase is the unzipping enzyme. DNA polymerase, replicates the DNA molecules to actually build a new strand of DNA. Primase acts as an initializer