Question

Sol.(d) [Key Concept: Sickle Cell Anaemia — Autosomal Inheritance] Sickle cell anaemia is inherited through AUTOSOMES (specifically chromosome 11). It is an autosomal recessive disorder — the mutant HbS gene is on chromosome 11. The HbS allele causes glutamic acid to be replaced by valine at the 6th position of the beta-globin chain. Both sexes are equally affected. It is NOT sex-linked (not on sex chromosomes), not in blood cells or bone cells (which carry the gene but don't 'inherit' it in the genetic sense).