What is a gene?

A gene is a small section of DNA which codes for a single protein. DNA is made up of a linear sequence of nucleic acids, which may be either A, T, C or G. Three nucleic acids make up a code for one amino acid. A sequence of amino acids joined up together makes a protein, and the type of amino acids which they are determines what the protein is. The protein produced may result in a particular characteristic in an individual. A gene may be copied and passed on to a daughter cell during reproduction, which will then display the same characteristic as the adult cell.