Structural genes, called mutations, may produce harmful, beneficial, or neutral effects to the structure and function of an organism. briefly describe the mutation to the hemoglobin gene that creates the sickle cell allele.

             Hemoglobin is an iron containing protein composed of four polypeptide chain and made from 574 amino acids. It play a key role in oxygen transport from lungs to all parts of the body. 

Mutation in hemoglobin:
                                      If mutation occurs in hemoglobin then glutamine amino acid is replaced by valine amino acid which lead to abnormal hemoglobin structure which is sickle shaped and can not pass through blood vessels resuting into deficiency of oxygen in the body and the disease called is known as sickle cell anaemia.

The answer is d. disruptive