Question

Explain how DNA can be used to identify an individual when 99% of living things have a common genetic code.

Answer 1

see there are small sections in our DNA called as the VNTR's
these are variable number of tandem repeats. we kind of inherit these repeats from our parents...so we check the repeats from our parent DNA and den we test ours...if both match then bingo u got the person...

Answer 2

see when u say 99% similar that means for eg
in mice ACGTATCGTTACC- codes for some protein lets say insulin
then in humans the same sequence would code for insulin...
also one thing i forgot to mention...these VNTR's are a part of the non coding region