untington's disease is a genetic disorder that can result in memory loss and abnormal body movements. Huntington's disease results from a defective gene (H) that is dominant to the allele that produces normal function (h). This means that...
I. if someone is heterozygous for Huntington's disease, then he/she will be a carrier but will not have the disease.
II. if a child has Huntington's disease, then at least one of his/her parents has the disease.
III. if two parents do not have Huntington's disease, then their children will not have the disease.
A.
I, II, and III
B.
I only
C.
III only
D.
II and III only
D. II and III only
Explanation:
I. If someone is heterozygous for Huntington's disease (Hh), then they will have the disease because the defective gene (H) is dominant.
II. If a child has Huntington's disease, then at least one of their parents must have the defective gene (H), as the gene is dominant.
III. If two parents do not have Huntington's disease and are both homozygous for the normal allele (hh), then their children will not have the disease as they will inherit the normal allele from both parents.