Answer
Chargaff's experiments showed that the concentrations of guanine and cytosine are equal and the concentrations of adenine and thymine are also equal. This supported Watson and Crick's idea of base pairing, according to which adenine always pairs with thymine and cytosine pairs with guanine in a DNA molecule, thus keeping A: T and C: G ratios close to 1. However, RNA is single-stranded and folds randomly, therefore Chargaff's rule would not be applicable as there is no base-pairing throughout the RNA molecule.
Work Step by Step
Nucleotides are classified into purines and pyrimidines. Purines include adenine and guanine. Pyrimidines include cytosine and thymine. Adenine and thymine pair through two hydrogen bonds, and guanine and cytosine pair through three hydrogen bonds.
