Question

Sol.(b) [Key Concept: Haemophilia — Recessive Not Dominant] Haemophilia is NOT a dominant disease — it is an X-LINKED RECESSIVE disease. Option (b) is the incorrect statement. Correct facts: (a) it IS recessive (males with one X^h allele are affected; females need two X^h alleles); (c) a single clotting protein is affected (Factor VIII in haemophilia A, Factor IX in haemophilia B); (d) it IS sex-linked (X-linked). Haemophilia's X-linked recessive pattern explains its higher prevalence in males.