Sickle cell disease provides an example for which principle of molecular genetics?

a. a point mutation always causes a significant change in phenotype.

b. a point mutation always causes a change to an amino acid sequence, which may affect phenotype.

c. a significant change in phenotype may cause a genetic mutation.

d. a change to one amino acid in a protein may cause a significant change in phenotype.

nevermind the answer is d.

The correct answer is D a change to one amino acid in a protein may cause a significant change in the phenotype.

Explanation:

Sickle cell anemia is caused by the replacement of 6th amino acid in the beta chain of hemoglobin that is glutamic acid by valine.

   glutamic acid is a hydrophilic amino acid that is being replaced by a hydrophobic amino acid known as valine.

   As a result the red blood cells  appear as insoluble aggregates which which ultimately result in the sickling of Red blood cells.That"s why this disease is named as sickle cell anemia.

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