True statement about inheritance of an X-linked recessive trait is:: (A) 50% of boys of carrier mother are affected, (B) 50% of girls of diseased father are carrier, (C) Father transmits disease to the son, (D) Mother transmits the disease to the daughter
Answer is A. For a X-linked recessive disease: If mother is a carrier: If father is diseased: 50% of boys of carrier mothers are affected All daughters are carriers Mothers transmit defective gene to 50% of the sons (diseased) as well as daughters (carriers) Fathers transmit defective gene to daughters