Q. 7.  Which of the following statements is the most appropriate for sickle-cell anemia?

(a) It cannot be treated with iron supplements

(b) It is a molecular disease

(c) It confers resistance to acquiring malaria

(d) All of the above 


(d) Sickle-cell anaemia is an autosome linked recessive trait. In this genetic disorder point mutation in β-globin chain results in a change of glutamate (glutamic acid) to valine at sixth position. Only the homozygous individuals for HbS2, i.e., HbSHbS show the diseased phenotype. The heterozygotes individuals HbS/HbA are carriers.

It is also known that heterozygotes, having both types of hemoglobin, show resistance to malaria infection because the body targets the P. falciparum (protozoan) infected cells for the destruction of RBC.