Despite the presence of a gene coding for the expression of a character, environmental factors such as temperature, sunlight, or humidity can affect whether the gene's potential is actually expressed. In this light, define the terms "penetrance" and "expressivity." How are individuals both a product of their genes and the environment?
Penetrance is the term for the percentage of people with genes coding for the expression of a character who actually express the character. Expressivity is term for the extent to which a phenotype is expressed. Variable expressivity can be due to other genetic differences, or environmental factors. Individuals are a product both of their genes and the environment because expressions of characters are dependent on the potentiality coded by the genes tempered by the influence of the environment.
