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.
The term entered popular culture with the publication in 1968 of The Double Helix: A Personal Account of the Discovery of the Structure of DNA, by James Watson. The DNA double helix polymer of nucleic acid, held together by nucleotides which base pair together. In B-DNA, the most common double helical structure found in nature, the double helix is right-handed with about 10â10.5 base pairs per turn. This translates into about 20-21 nucleotides per turn.