Scientists use dna sequencing to understand relationships among life on earth. the chart illustrates differences between five species and humans. although the dna sequence of each may vary, what statement about all six organisms is true? a) the dna sequences may vary but the amino acid sequences are identical. b) the nitrogen bases in the nucleotides must also be different in each. c) the process in producing additional dna, replication, is identical in all six. d) the process of producing dna, or replication, varies due to the differences in the dna codes.