Why do offspring have different phenotypes from their parents or siblings?
Explore codominance by investigating the inheritance of sickle cell disease within a family.
Codominant alleles are both expressed in a persons phenotype.A heterozyygous will have the traits associated with both alleles.In this lab,you will explore codominance by analyzing the results for the sickle cell disease within a family
Sickle cell disease is caused by a change in the gene for hemoglobin,which is the oxygen-carrying protein in red blood cells.Individuals who are homozygous for the sickle cell trait often cannot exercise.Individuals who are heterozygous for the trait can have sickle cell attacks under extreme conditions.Normal individuals (HbS Hbs) have only normal hemoglobin.Homozygous sickle cell individuals (HbS Hbs) have only sickle cell hemoglobin.Heterozygous individuals (HbS Hbs) have both normal and sickle cell hemoglobin.
Jerry smith collapsed while running a race for his track team.A doctor said that he had a sickle cell attack.Genetic tests were run on several family members.The tests results are shown below.An X indicates that from a hemoglobin in red blood cells.
How can you determine the genotypes of people on the family?
Jerry Smith HbS Hbs
Jerry's brother HbS HbS
Jerry's younger sister HbS Hbs
Jerry's father HbS HbS
Jerry's grandfather HbS HbS
Jerry's grandmother HbS Hbs
1 Use the background information and the genetic tests results to answers questions 1-4.
2 Use the background information and a punnet square to help you answer question 5
1 Are any of Jerry's sibling homozygous for the sickle cell trait?Are any of jerry's sibling