Chargaffs rules states that dna from any cell of all organisms should <span>have a 1:1 ratio (base Pair </span>Rule<span>) of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine.</span>
When scientists measure, they use the metric system.
A. Cell membrane would be the answer.
