Hemoglobin Is a Model System to Illustrate the Deleterious Effects

Multiple Choice

Hemoglobin is a model system to illustrate the deleterious effects of mutations.Which of the following statements about deleterious mutations in human hemoglobin genes is false?

A) Hemoglobin A and hemoglobin S differ at only one amino acid position
B) In hemoglobin S, the substitution of valine for glutamic acid causes an aggregation of hemoglobin molecules not found in hemoglobin A
C) The molecular difference between hemoglobin A and hemoglobin S was identified by protein sequence before nucleotide sequence
D) The valine to glutamic acid substitution is the only amino acid change so far identified in the b chain of hemoglobin
E) Homozygous (Hb^sb/Hb^sb) leads to severe hemolytic anemia, which is often fatal.