The phenomenon in which some individuals with a particular genotype fail to display the corresponding phenotype is called incomplete penetrance.
<u>Explanation:</u>
Penetrance is a concept in which a certain population who has a particular changed gene sequences that yield a genetic disorder. In such cases there is a particular population who does not exhibit the phenotypic changes that corresponds to their genotypic changes such a phenomenon is termed as incomplete penetrance for example not all people who have a mutation in the BRACA 1 gene have breast cancer.
