Answer
See explanation
Work Step by Step
From Chargaff's experiments, the purine (A/T) and pyrimidine (G/C) ratios are close to 1. This implies that the concentration of guanine and cytosine residues are equal and that the concentration of adenine and thymine residues in the DNA are also equal. However, the A: G and T: C ratios are far greater than 1, which implies that the concentrations of adenine and guanine are not the same. Likewise, the concentration of thymine and cytosine is also not the same. The data, therefore, go against Levene's tetranucleotide model which proposed that the concentration of all nucleotides in the DNA would be the same.
Consequently, as the A: G and T: C ratios vary among organisms, the primary structure of DNA varies between organisms.
