Sickle cell disease is inherited as an autosomal recessive trait.The genotype of an individual with sickle cell disease is
A) homozygous dominant.
B) homozygous recessive.
C) heterozygous dominant.
D) heterozygous recessive.
E) unable to be determined by the phenotype.

Question

Quizplus · Accepted Answer

Sickle cell disease is caused by a mutation in the beta-globin gene (HBB) that results in the production of abnormal hemoglobin (HbS). The HBB gene is located on chromosome 11 and individuals inherit two copies (alleles) of this gene, one from each parent. Since sickle cell disease is an autosomal recessive disorder, an individual with the disease must have two recessive alleles (ss), one from each parent. Therefore, the genotype of an individual with sickle cell disease is homozygous recessive.

Sickle Cell Disease Is Inherited as an Autosomal Recessive Trait