Tay-sachs is a recessive lethal disease. it leads to neurological deterioration soon after birth and death usually by the age of 4. this disease is rare in the population overall but is found at relatively high frequency in ashkenazi jews from central europe. a woman whose maternal uncle had the disease is trying to determine the probability that she and her husband could have an affected child. her father does not come from a high-risk population. her husband's sister died of the disease at an early age.

required:
a. draw the pedigree of the individuals described. include the genotypes where possible.
b. determine the probability that the couple's first child will be affected.