In which phase of the cell cycle does replication

In which phase of the cell cycle does replication occur in eukaryotes? What would happen if cell division is not followed after DNA replication?

DNA replication occurs in S-phase of cell cycle in eukaryotes. If cell division is not followed after DNA replication then the replicated chromosomes (DNA) would not be distributed to daughter nuclei. A repeated replication of DNA without any cell division results in the accumulation of DNA inside the cell, thereby causing cell expansion.