Final answer:
Retinoblastoma is an eye cancer that is usually inherited as a dominant trait. However, it has an unusual inheritance pattern because it requires two mutations to develop.
Step-by-step explanation:
Retinoblastoma is an eye cancer that is usually inherited as a dominant trait. However, it has an unusual inheritance pattern because it requires two mutations to develop. One mutation can be inherited from a parent who carries the mutated gene, but the second mutation occurs spontaneously during the child's development and leads to the development of retinoblastoma. This makes the inheritance of retinoblastoma seem like a recessive trait.