Final Answer:
The four nucleotides are Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). According to the Base-Pairing Rule, Adenine pairs with Thymine (A-T), and Guanine pairs with Cytosine (G-C).
Step-by-step explanation
The genetic information in DNA is encoded through the sequence of nucleotides, which are the building blocks of DNA. There are four types of nucleotides, each distinguished by their nitrogenous bases: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). The Base-Pairing Rule, a fundamental principle in molecular biology, dictates how these nucleotides pair up. Adenine always pairs with Thymine (A-T), and Guanine always pairs with Cytosine (G-C).
This pairing specificity is essential for maintaining the structural integrity and functionality of the DNA molecule. The specificity arises from hydrogen bonding between the complementary bases. Adenine forms two hydrogen bonds with Thymine, and Guanine forms three hydrogen bonds with Cytosine. This complementary base pairing ensures that the two strands of the DNA double helix are held together with precision. The pairing is often represented visually as A-T and G-C, reflecting the specificity and consistency of these interactions.
Understanding the Base-Pairing Rule is crucial for various biological processes, including DNA replication and transcription. During DNA replication, the strands unwind, and each strand serves as a template for the synthesis of a new complementary strand. The fidelity of this process relies on the accurate base pairing dictated by the A-T and G-C rule. In summary, the Base-Pairing Rule is a foundational concept in molecular genetics, defining how the four nucleotides interact to encode genetic information in the DNA molecule.