Which of the following facts relates to Chargaffs rule?

A. DNA contains a pentose sugar, nitrogenous bases, and a phosphate group

B. DNA is a molecule in structure

C. DNA contains thymine, cytosine, adenine, and guanine

D. Cytosine and guanine appear in equal proportions in DNA

The correct answer is D. Cytosine and guanine appear in equal proportions in DNA.

Explanation:

Chargaff's rules state the relationship that exists between the nucleotides that make up DNA:

The amount of Adenine (A) is equal to the amount of Thymine (T), and the amount of Guanine (G) is equal to the amount of Cytosine (C). In synthesis: the total number of purine bases is equal to the total number of pyrimidine bases:

A + G = C + T