| the spiral arrangement of the two complementary strands of DNA. |

| double helix n. The coiled structure of double-stranded DNA in which strands linked by hydrogen bonds form a spiral configuration, with the two strands oriented in opposite directions. |
double helix n.
The coiled structure of a double-stranded DNA molecule in which strands linked by hydrogen bonds form a spiral configuration. Also called DNA helix, Watson-Crick helix.