Brown-eyed right-hander, married to the same woman. The first child was born blue-eyed left-handed.

Brown-eyed right-hander, married to the same woman. The first child was born blue-eyed left-handed. what is the likelihood that the next children will be like their parents. Dominant features: brown eyes, and right-handed.

Let’s designate brown-eyed as “A”, right-handedness as “B”, then blue-eyed will be designated “a”, left-handedness – “b”.

A left-hander with blue eyes, as having both recessive traits, will have the aavv genotype. Homozygosity is a condition under which a recessive trait acquires the ability to be realized in a phenotype.

Since the child inherited one of a pair of recessive genes from each of the parents, it should be concluded that both parents are heterozygous for both traits and their genotypes are as follows: AaBv.

Each of the parents produces germ cells of the following species: AB, AB, AB and AB.

When such gametes merge, all possible phenotypic variants can be obtained: brown-eyed right-handers, blue-eyed right-handers, brown-eyed left-handers and blue-eyed left-handers. These phenotypes listed in order will be a ratio of 9: 3: 3: 1.

Let’s solve the mathematical proportion and find out the probability of birth in this pair of brown-eyed right-handers will be (9 * 100) / 16 = 56.25%.

Answer: 56.25%.