Credit: Kateryna Kon/Science Photo Library/ What is DNA, and how does it work? You don't need a degree in ...

The basic units (monomers) of DNA are nucleotides. These nucleotides consist of a deoxyribose sugar, phosphate and base. The nucleotides are identical except for the base, which can be an adenine ...

A simple polyester can be made from a monomer which has two hydroxyl groups (-OH) and another monomer which has two carboxylic acid groups (-COOH).

There is a considerable amount of evidence to show that for a given polymer the density of cross-linking (that is, the proportion of monomer units ... of known average molecular weight.