What is the significant of the number and location of RFLPs a particular individual has in its genome? A polymorphism is a genetic characteristic that varies among individuals in a population. For some polymorphisms there are major consequences in having one genotype versus another. Many genetic diseases are the result of a polymorphism at a single locus. For example individuals that are homozygous for the sickle cell allele have a serious illness while individuals that are homozygous for the ‘normal’ allele or are heterozygous do not have the illness. Restriction sites are short sequences recognized by restriction enzymes. Because these sequences are fairly short they are likely to appear by chance at random locations in the genome due to mutation. Restriction mutations in protein coding regions may be removed by natural selection if they result in a less functional product. Otherwise the RFLP differences among individuals have no functional significance. They are useful in DNA fingerprinting but do not affect the organism.