Ais a series of nucleotides that encodes a protein product. This coding DNA may have different forms, or varieties, called. An individual with two different versions of a gene is genetically. In traits with a simple pattern of inheritance, only the trait conferred by theform of the gene will be visible. The other form of the gene is: it confers a trait that is only visible when the individual is genetically, or has two identical copies of the gene.