Results from the Study of Globin Variants Indicate That ____

Question

Results from the study of globin variants indicate that ____.
A) all amino acid substitutions cause severe phenotypic effects
B) a change in a single nucleotide is sufficient to cause a genetic disorder
C) extended chains of phosphorus molecules function to carry oxygen
D) all of the changes in globin are due to changes in amino acid sequences
E) sickle cell anemia is not primarily an inherited disease

Accepted Answer

The study of globin variants has shown that a change in a single nucleotide (i.e. a point mutation) can cause a genetic disorder, as seen in the case of sickle cell anemia. Not all amino acid substitutions cause severe phenotypic effects, and not all changes in globin are due to changes in amino acid sequences (for example, some variants result from changes in regulatory elements). Extended chains of phosphorus molecules do not function to carry oxygen. The last option, that sickle cell anemia is not primarily an inherited disease, is incorrect as sickle cell anemia is indeed an inherited genetic disorder.