Final answer:
DNA's structure is a double helix where two strands are connected by hydrogen bonds in a specific base pairing: A-T and C-G, important for replication and DNA function.
Step-by-step explanation:
The structure in question is the double helix structure of DNA, discovered by James Watson and Francis Crick in 1953. DNA consists of two long strands of nucleotides that twist around each other to form a helix.
The strands are connected by hydrogen bonds between nitrogenous bases, following the base pairing rules: adenine (A) to thymine (T) and cytosine (C) to guanine (G). Each A-T pair is held together by two hydrogen bonds, whereas each C-G pair is held together by three hydrogen bonds. This arrangement is essential for DNA replication and function.