Tay-Sachs disease is inherited as an autosomal recessive. It is a devastating neurological disease that results from the lack of a normal enzyme, hexosaminidase A, whose job is to metabolize lipids (gangliosides) that are found in brain cells. A young couple is told that they are carriers for this disease. Explain, as you would to this couple, their likelihood of having a child with Tay-Sachs disease. Show the Punnett square that illustrates their chances.

Based on your understanding of sex linkage, describe in detail why most hemophiliacs are male. Can females have hemophilia? Describe how they could inherit this disorder. Can males be carriers for hemophilia? Explain.