What kind of helix in dna

Of course, this is Watson and Crick's incredible realization back in , but it will stand in history as probably one of the most significant scientific moments of all time. Francis S. Collins, M. Chapter Natural Selection. Chapter Population Genetics. Chapter Evolutionary History. Chapter Plant Structure, Growth, and Nutrition. Chapter Plant Reproduction. Chapter Plant Responses to the Environment. Full Table of Contents. This is a sample clip.

Sign in or start your free trial. JoVE Core Biology. Next Video. Embed Share. Deoxyribonucleic acid, or DNA, consists of two polynucleotide chains. Please enter your institutional email to check if you have access to this content. Please create an account to get access. Forgot Password? Please enter your email address so we may send you a link to reset your password.

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After her death, Crick said that her contribution had been critical. The double helix describes the appearance of double-stranded DNA, which is composed of two linear strands that run opposite to each other, or anti-parallel, and twist together.

Each DNA strand within the double helix is a long, linear molecule made of smaller units called nucleotides that form a chain. The chemical backbones of the double helix are made up of sugar and phosphate molecules that are connected by chemical bonds, known as sugar-phosphate backbones. The nitrogen bases can only pair in a certain way: A pairing with T and C pairing with G.

Due to the base pairing, the DNA strands are complementary to each other, run in opposite directions, and are called antiparallel strands. Show Sources Boundless vets and curates high-quality, openly licensed content from around the Internet. October 16, Licenses and Attributions.