In people with maple syrup urine disease, the body is unable tometabolize the amino acids leucine, isoleucine, and valine. One ofthe symptoms is that the urine smells like maple syrup. An unaffected couple produced six children in the following order: unaffecteddaughter, affected daughter, unaffected son, unaffected son, affectedson, and unaffected son. The youngest unaffected son and an unaffected woman have three children in the following order: affecteddaughter, unaffected daughter, and unaffected son. Draw a pedigreethat describes this family. What type of inheritance (dominant orrecessive) would you propose to explain maple syrup urine disease?

Sickle cell anemia is caused by an individual carrying two recessive copies of the hemoglobin gene (hemoglobin gene is labeled Hb, and the recessive version is Hbs). Thus, to have sickle cell anemia, a person must have the genotype HbSHbS. A person that is HbAHbA carries two copies of the normal hemoglobin gene and does not have sickle cell anemia. A person that is heterozygous (HbAHbS) produces enough normal hemoglobin to not have sickle cell anemia but is also resistant to malaria. People that are heterozygous are called “carriers” because they carry the recessive allele but do not express the recessive phenotype. a. A couple are both resistant to malaria but do not have sickle cell anemia. Draw a Punnett square to represent this cross. b. What is the probability that the couple has three children where one child does not have a recessive allele, one child is resistant to malaria and does not have sickle cell anemia, and one child has sickle cell anemia?

Given the information regarding sickle cell anemia, if two carriers were to have children, what would be the genotypes and phenotypes of their children? Would any of the children show symptoms of the disease?

what is the probability that a couple (both heterozygous for the same recessive mutation) will have two children with the disease if the couple plans to have four children in total?