Final answer:
DNA's sequence is crucial as it encodes the genetic instructions vital for all biological functions and heredity, essentially acting as a blueprint for protein synthesis.
Step-by-step explanation:
Sequence.
DNA, or deoxyribonucleic acid, carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms, as well as many viruses. DNA's sequence—the order of nucleotides along a DNA strand—is critical because it determines the genetic instructions encoded within a particular segment of DNA. This sequence specifies the order in which amino acids are to be linked together to form a protein. Each of the four different types of nucleotides—adenine (A), cytosine (C), guanine (G), and thymine (T)—corresponds to a particular genetic 'letter' that, strung in a particular sequence, forms 'words' and 'sentences' known as genes.
Variations in the sequence of these nucleobases can change the instruction which, in turn, affects the type and function of a protein produced. Therefore, understanding the sequence of DNA provides the most fundamental level of knowledge about its role in heredity and protein synthesis, thereby elucidating its function in a biological context.