AP BIOLOGY

Detailed explanation-1: -Family history. Hunter syndrome is caused by a defective chromosome, and a child must inherit the defective chromosome to develop the disease. Hunter syndrome is what’s known as an X-linked recessive disease, which means that women carry the defective disease-causing X chromosome and can pass it on.

Detailed explanation-2: -Recessive alleles only show their effect if the individual has two copies of the allele (also known as being homozygous?). For example, the allele for blue eyes is recessive, therefore to have blue eyes you need to have two copies of the ‘blue eye’ allele.

Detailed explanation-3: -Some health problems are passed down through families. There are different ways this can happen. To have a child born with what’s called an “autosomal recessive disease” like sickle cell disease or cystic fibrosis, both you and your partner must have a mutated (changed) gene that you pass on to your child.