Florence (Firenze) 10 day weather forecast, updated four times a day and shows the weather summary plus detailed sun, rain, snow, wind and temperature. The weather forecast extends out to 10 days showing information for morning, afternoon and overnight.
Definition of double helix. : a helix or spiral consisting of two strands in the surface of a cylinder that coil around its axis; especially : the structural arrangement of DNA in space that consists of paired polynucleotide strands stabilized by cross-links between purine and pyrimidine bases â compare alpha-helix, watson-crick model.
double 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. The shape taken by the DNA molecule.