Question

4.How might similarities and differences in genetic codes, or the proteins built as a result of these codes, be used to determine how closely related different species are?

Answer 1

To compare different species, scientists cut the DNA of the species into small segments, separate the strands, and mix the DNA together. When the two species' DNA bonds together, the match between the two strands will not be perfect since there are genetic differences between the species - and the more imperfect the match, the weaker the bond between the two strands.

These weak bonds can be broken with just a little heat, while closer matches require more heat to separate the strands again.