Definition for Chargaff's rules
From Biology Forums Dictionary
1. The percentage of adenine is equal to that of thymine and the percentage of guanine is equal to that of cytosine.
2. The equivalences for any given species between the number of adenine and thymine bases and the number of guanine and cytosine bases became known as Chargaff's rules. The basis for these rules remained unexplained until the discovery of the double helix (DNA).
