Final answer:
The percentage of individuals having a particular genotype that express the expected phenotype is penetrance.
Step-by-step explanation:
The percentage of individuals having a particular genotype that express the expected phenotype is penetrance.
In genetics, penetrance refers to the extent to which a particular genotype is expressed in the phenotype. It is a measure of the likelihood that a particular genotype will produce the expected phenotype. For example, if all individuals with a certain genotype show the expected phenotype, then the penetrance is 100 percent. If only some individuals with that genotype show the expected phenotype, then the penetrance is less than 100 percent.
Example:
In a cross between individuals with the genotypes AA and aa, all of the offspring will have the genotype Aa. If all of the Aa individuals show the phenotype of the dominant allele, then the penetrance of the genotype Aa is 100 percent.