Question

The Smith family is afflicted with a genetic disorder known as Pinocchio nose syndrome, which causes affected adults to grow noses in excess of five inches long. 100 members of the Smith family show up for a family reunion. Of the fifty-three women, thirty-seven have unusually large noses. Of the forty-seven men, thirty-six have an enormous nose. Based on these figures, Pinocchio nose syndrome is probably
A)88dominant and sex-linked.
B) recessive and sex-linked.
C) dominant, but not sex-linked.
Eliminate
D) recessive, but not sex-linked.

Answer 1

The answer is letter B.

Since both sexes in the family are affected of the syndrome, it is considered as a recessive and sex-linked genetic trait. This simply means that the disease was passed down through families through one of the X or Y chromosomes (sex chromosomes). This occurs even if one parent has a normal gene but the other has an abnormal gene that carries the disease, the abnormal gene then dominates.