The feature of model 1 that best illustrates how biological information is coded in a DNA molecule is the linear sequence of the base pairs. This sequence determines the genetic code, as each base pair (adenine, thymine, cytosine, guanine) in a specific order encodes instructions for building proteins through codons—triplets of bases that correspond to amino acids. The linear arrangement of these base pairs is fundamental because it carries the biological information necessary for protein synthesis and cellular function
. Other structural features of DNA, such as the 5′ and 3′ ends, hydrogen bonds between base pairs, or covalent bonds in the backbone, are important for DNA stability and replication but do not directly represent the coded biological information. The informational content lies specifically in the order of the bases along the DNA strand
. Thus, the linear sequence of base pairs in model 1 best exemplifies how biological information is encoded in the DNA molecule.
