Question

why it is essential that a DNA copy of a existing DNA molecule is created

Answer 1

bcz dna consist gene

Answer 2

DNA, the double-stranded molecule, has the unique ability to replicate itself. That is, DNA can make exact copies of itself. This is important, for instance, for the function of biological reproduction and cell growth. The replication function occurs when the hydrogen bond that exists between nucleotide bases is broken, which results in the two DNA strands existing as separate single strands of DNA.