Final answer:
The base complementarity rule guides the specific bonding of base pairs in DNA, with A pairing with T via two hydrogen bonds and G pairing with C via three hydrogen bonds, ensuring the integrity and replication of the DNA molecule.
Step-by-step explanation:
The principal that guides the specific bonding of base pairs in DNA is called the base complementarity rule. In this rule, adenine (A) always pairs with thymine (T), and guanine (G) always pairs with cytosine (C). This precise pairing occurs due to the formation of hydrogen bonds, where A and T are connected by two hydrogen bonds and G and C are connected by three. The accurate pairing is crucial because it ensures that the DNA's double helix has a uniform diameter and can effectively replicate during cell division, thereby preserving genetic information.
The structure of DNA as proposed by Watson and Crick is a right-handed helix consisting of a sugar-phosphate backbone with the nitrogenous bases paired in the interior. These complementary base pairs maintain the DNA's consistent structural integrity, allowing for essential biological processes such as mitosis, transcription, and translation.