|biochem the form of the molecular structure of DNA, consisting of two helical polynucleotide chains linked by hydrogen bonds and coiled around the same axis|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
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.
The three-dimensional structure of double-stranded DNA, in which polymeric nucleotide strands whose complementary nitrogen bases are linked by hydrogen bonds form a helical configuration. The two DNA strands are oriented in opposite directions.