Final answer:
In a DNA structure with mostly C-G base pairs, there is increased stability due to three hydrogen bonds per pair, which is in alignment with Chargaff's Rules and contributes to the uniformity of the double helix.
Step-by-step explanation:
When DNA is constructed to have mostly C-G base pairs, it exhibits a higher stability due to the presence of three hydrogen bonds that form between cytosine and guanine, compared to the two hydrogen bonds between adenine and thymine. This is consistent with Chargaff's Rules, which states that in DNA, the amount of guanine is equal to the amount of cytosine, and the amount of adenine is equal to the amount of thymine.
These rules are a direct consequence of base-pairing specificity, whereby adenine pairs exclusively with thymine, and guanine pairs exclusively with cytosine, ensuring a uniform diameter throughout the DNA double helix. The DNA double helix structure, as proposed by Watson and Crick, is made up of two antiparallel strands, forming a right-handed helix, stabilized by the hydrogen bonding of these complementary base pairs.