Question

Neurofibromatosis is a genetic disorder associated with an allele on an autosomal chromosome. Individuals with neurofibromatosis have uneven skin pigmentation and skin tumors. A man with neurofibromatosis marries a woman who does not carry the allele for this disorder. The couple has 5 children, 3 of whom have neurofibromatosis. The most likely explanation for this outcome is that neurofibromatosis is a ________ trait and the man is ________.

Answer 1

autosomal dominant, affected

Step-by-step explanation:

Neurofibromatosis is an autosomal (non-sex chromosome) dominant disease, which means that a single mutant gene from the parents can cause the disease in the next generation. And there is a 50% chance of passing the affected genes to the children.

In this case, since we know the mother does not carry the mutant allele, and just one copy of the affected allele is enough for the children to have neurofibromatosis. We can conclude that the father carries the mutant allele and 3 of the 5 children, inherited the afected allele and have the disease.