DNA stands for deoxyribonucleic acid, which is the molecule that carries genetic information in humans and all other living organisms. Deoxyribonucleic acid is composed of four chemical bases: adenine, guanine, cytosine and thymine. The sequence of these bases within DNA encodes genetic information.Continue Reading
Human genomes comprise approximately three billion chemical bases. More than 99 percent of human DNA is identical from individual to individual.
The structure of DNA consists of two connected strands of chemical bases which form a spiral known as a double helix. The double helix structure of DNA was discovered by Francis Crick and James Watson in 1953.
Many viruses do not contain any DNA, and instead rely on RNA. RNA is very similar to DNA and like DNA is essential to all forms of life but is single rather than double-stranded and makes use of uracil as a chemical base in place of thymine.Learn more about Cells