What structure is formed by strands of DNA held together by hydrogen bonding?

The formation of a double helix structure is foundational to the understanding of DNA. In this configuration, two strands of DNA are intertwined, with each strand made up of a long sequence of nucleotides. The strands are held together by hydrogen bonds that form between complementary base pairs: adenine pairs with thymine, and cytosine pairs with guanine. This base pairing is crucial for the stability of the DNA molecule and allows for the precise replication of genetic information during cell division.

The double helix structure was famously described by James Watson and Francis Crick, and it not only provides a means for storing genetic information but also plays a significant role in how that information is accessed and expressed within a cell. This structure allows DNA to be compactly stored within the nucleus of eukaryotic cells while still being accessible for transcription and replication processes.

In contrast, the other options describe structures that are not typical for DNA. A single helix, while it may refer to certain RNA structures, does not apply to DNA, which is always double-stranded under physiological conditions. Triple and quadruple helix structures may form under specific conditions or with certain types of nucleic acids, but they are not representative of the canonical structure of DNA that is