Examples All your body's characteristics are affected by one or more genes. For example, genes control your eye color, blood group, height and even your IQ. For example, the gene CCACACGCCGGC may code for protein A which in turn produces a blue pigment in your eyes, and gives you blue eyes. But your friend may have the gene CCATAGGCCGGC instead, and this will produce a different protein B, which may produce a black pigment. Your friend will thus have black eyes. 　 CCACACGCCGGCProtein A Blue pigmentBlue Eyes 　 　 CCATAGGCCGGCProtein B Black pigmentBlack Eyes 　 Relating Topics - Dominant and Recessive Alleles - Examples of Traits