Why is DNA replication essential for a cell?
The genetic material of all cells is deoxyribonucleic acid or DNA.
The quantity of DNA is the same in all cells of an individual, except in the egg and sperm, which contain only half the amount.
When cell division occurs, the DNA replicates itself, producing two identical DNA molecules that are transmitted [passed on] from the parent cell to the daughter cells.
Without this process, there would be no way that our cells could continue to produce other cells, because the DNA acts as a blueprint for protein synthesis as well as various cell functions.
Hence, DNA replication is essential.
This video provides a brief summary of this process using the DNA Workshop activity from PBS.
I hope this helps!