MAIN FUNCTION OF GENES

The main function of genes is to provide the information needed to make molecules called proteins in cells.Proteins are made of a chain of 20 different types of amino acids molecules.The information in DNA is held in the sequence of the repeating units along the DNA chain. These units are four types of nucleotides((A,T,G and C) and the sequence of nucleotides stores information in an alphabet called the genetic code. When a gene is read by a cell the DNA sequence is copied into a very similar molecule called RNA.If the sequence of the nucleotides in a gene changes, the sequence of the amino acids in the protein it produces may also change - if part of a gene is deleted, the protein produced will be shorter and may not work any more