Scientist sometimes use DNA sequences such as these to determine the relatedness of different species. Which of the following is a necessary on for scientists to use DNA sequences in this way?

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

the animal that would be cutest if scaled down to the size of a cat? elephant