Question

Why is it necessarry for DNA to replicate itself?

Answer 1

Like Many time's I've looked the answer up ;)

DNA replication needs to occur because existing cells divide to produce new cells. ... So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!

Answer 2

Producing exact copies of DNA ensures that when a cell divides, the offspring will receive the same genetic information as the parent cell. ... They will always match up with each other in the DNA strands.

DNA replication needs to occur because existing cells divide to produce new cells. Each cell needs a full instruction manual to operate properly. So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!