There are four types of base - adenine, thymine, cytosine and guanine. All human cells contain DNA. The 3 billion pairs of bases in each cell fit into a space that is six microns across.

A DNA sequence is a specific lineup of chemical base pairs along its strand. The part of DNA that determines what protein to produce and when, is called a gene. First established in 1985 by Sir ...

Comparison of a single-stranded RNA and a double-stranded DNA with their corresponding nucleobases. (Image: Wikimedia Commons, CC SA 3.0) The most common type of base pairing is the Watson-Crick base ...

They worked out that in a DNA molecule: there are two strands the strands are twisted around each other to form a double helix the strands are held together by bonds between base pairs Back to top ...

This discovery, along with the identification of other nitrogenous bases, laid the foundation for ... or the hydrolysis of 2-amino-4,6-dichloropyrimidine. Cytosine can also be isolated from DNA or RNA ...