Answer/Explanation:
DNA is replicated through semi-conservative replication. This produces two copies of a double stranded DNA molecule, each possessing one copy of the original molecule. This occurs prior to the cell dividing, in the synthesis stage of the cell cycle.
Enzymes use the original DNA molecule as a template to produce a new strand of DNA. This occurs through the progressive addition of nucleotides, which are added as complementary base pairs matching the template strand. This means the new strand is complementary to the template strand. This processes is generally free of errors, but errors can be introduced during replication, causing mutations in the DNA.