Several members of a family have polydactyly, and they differ in their numbers of extra fingers and toes. Yet, certain relatives who should have extra digits don't, such as Megan. Megan's father has an extra digit on each hand and foot, and she has two children, a son with two extra fingers and a daughter with an extra toe. Polydactyly in this family is:
Multiple Choice
variably expressive and incompletely penetrant
pleiotropic and a phenocopy
dominant and recessive
invariably expressive and completely penetrant
