Wooly-hair is a rare trait found in people of Scandinavian descent in which the hair resembles the wool of a sheep. A woman with wooly hair who has a mother with straight hair moves to an island inhabited by people who are not of Scandinavian descent. She marries and produces both wooly-haired and straight-haired children. Her wooly-haired daughters have wooly-haired grandchildren of both sexes but her wooly-haired sons pass the trait only to their daughters.

Propose a mode of inheritance for this disease.