Apply the laws of probability and calculate the probability

Apply the laws of probability and calculate the probability that the offspring of cousins III-3 and III-5 will have the trait?
(enter number between 1.00 and 0.00)

Apply the laws of probability and calculate the probability that the offspring of cousins III-1 and III-7 will have the trait?
(enter number between 1.00 and 0.00)

Solution

The pedigree suggests that it is dominant autosomal heritance trait. The first generation has female homozygous AA and male is heterozygous Aa. It is because all offspring (2^nd generation) are diseased. But the male one is heterozygous Aa and the female which is married to him is also heterozygous Aa. Now the cross between both have offspring AA(1) aa(2) Aa(3).

Aa x Aa = AA, aa, Aa

On the other hand female of 2^nd generation who married to a male (no disease), has Aa genotype. It is because the offspring from both have two females and one male diseased. Male should get it from mother. The trait cannot said to X linked because there is one female have no disease. So, Aa(4), aa(5), Aa(6), Aa(7)

Aa x aa = Aa, aa   

Now cross between III-3 and III-5 which is Aa x aa

Offspring = Aa, aa so there is 50% chances of having disease to any child.

Number of dominant genotype/ total genotypes = ½ = 0.50

Now cross between III-1 and III-7 which is AA x Aa

Offspring = AA, Aa so there is 100% chances of having disease to any child

Number of dominant genotype/ total genotypes = 2/2 =1