The average distance between base pairs along the long (helical) axis of DNA is 3.4 Å. The average molar mass of a pair of nucleotides is 660 g/mol. (a) (b) (c) set If the human body contains 0.5 g of DNA, what is the total length of DNA in a human body? Compare this length with the distance from the earth to the moon (380 000 km). Compare the length of DNA in a single human cell (~ 3 billion base pairs for each haploid of chromosomes) to the diameter of the nucleus (~6 µm).