Tay-Sachs disease is a rarehuman disease in which toxic substances accumulate in nerve cells.The recessive allele (t) responsible for the disease is inheritedin a simple Mendelian manner. A woman is planning to marry herfirst cousin, but the couple discovers that their sharedgrandfather’s sister died in infancy of Tay-Sachs disease. What isthe probability that the cousins’ first child will have Tay-Sachsdisease? Use T and t as your gene symbols.