Final answer:
G:C base pairs are more stable than A:T base pairs because G:C pairs form three hydrogen bonds compared to two in A:T pairs, providing additional stability via stronger electrostatic attraction.
Step-by-step explanation:
Guanine:Cytosine (G:C) base pairs are more stable than Adenine:Thymine (A:T) base pairs due to the number of hydrogen bonds formed between them. Hydrogen bonds are a type of chemical bond that is responsible for the stability of the DNA double helix structure. According to Watson and Crick's model of DNA, these base pairs are stabilized by hydrogen bonds, with A:T forming two hydrogen bonds and G:C forming three. This additional hydrogen bond in G:C pairs contributes to a higher binding energy, leading to increased stability of these pairs compared to A:T pairs.
Furthermore, the complementary base pairing rules, which are a fundamental aspect of DNA's structure and replication process, ensure that adenine (A) always pairs with thymine (T) and guanine (G) pairs with cytosine (C) in the DNA helix. This specific pairing is essential for preserving the order of bases during cell division and allowing DNA to replicate accurately. The extra hydrogen bond between G and C creates a stronger electrostatic attraction, which is why G:C base pairs exhibit more stability than A:T pairs.