Question

which of the following can you conclude about the hemoglobin in individuals with sickle cell anemia? select the two correct answers. a the amino acids sequenced for the abnormal hemoglobin replaced a glutamic acid (glu) for a leucine (leu). b the amino acids sequenced for the abnormal hemoglobin replaced a glutamic acid (glu) for a valine (val). c the amino acids sequenced for the abnormal hemoglobin was the same as it was for the normal hemoglobin. d there was an error in the nucleotide sequence in the original dna strand

Explanation:

Sickle cell anemia is a genetic disorder. In sickle - cell hemoglobin (\(HbS\)), a single nucleotide substitution in the DNA leads to a change in the amino acid sequence of the beta - globin chain. The normal amino acid glutamic acid (Glu) at the 6th position of the beta - globin chain is replaced by valine (Val). This is due to a point mutation in the DNA (a change in the nucleotide sequence).

• Option A: The substitution is Glu to Val, not Glu to Leu. So, option A is incorrect.
• Option B: In sickle - cell hemoglobin, Glu is replaced by Val. This is correct.
• Option C: The amino acid sequence of abnormal (sickle - cell) hemoglobin is different from normal hemoglobin. So, option C is incorrect.
• Option D: The root cause of the abnormal hemoglobin in sickle cell anemia is an error (a point mutation) in the nucleotide sequence of the DNA that codes for the beta - globin chain. This is correct.

Answer:

B. The amino acids sequenced for the abnormal hemoglobin replaced a Glutamic acid (Glu) for a Valine (Val).
D. There was an error in the nucleotide sequence in the original DNA strand.