The term "Double Helix" refers to the shape of a DNA molecule, which looks like a twisted ladder or spiral staircase. DNA, which stands for deoxyribonucleic acid, is the molecule that carries genetic information in living organisms. The "sides" of the ladder are made of sugar and phosphate groups, while the "rungs" consist of pairs of chemical bases called adenine (A), thymine (T), cytosine (C), and guanine (G). In a DNA double helix, A always pairs with T and C always pairs with G. This structure helps DNA to be stable and efficient at storing genetic information, guiding the development and functioning of all living things.
Examiner-written GCSE Biology revision resources that improve your grades 2x
- Written by expert teachers and examiners
- Aligned to exam specifications
- Everything you need to know, and nothing you don’t
Share this article
written revision resources that improve your