Question

Sol.(c) [Key Concept: X-linked Genes — Haemophilia and Colour Blindness] From the karyotype diagram showing X and Y chromosomes, genes a and b are located on the X chromosome (in the X-specific region, not present on Y). Genes located on the X chromosome (X-linked genes) include: haemophilia A (Factor VIII gene), haemophilia B (Factor IX gene), and red-green colour blindness (opsin genes). Both haemophilia and red-green colour blindness are X-linked recessive traits. Body height, ear lobe attachment, Rh blood group, and PKU are autosomal, not X-linked.