In humans, myopia prevails over the norms of vision, and right-handedness over right-handedness.

In humans, myopia prevails over the norms of vision, and right-handedness over right-handedness. The signs are determined by unlinked autosomal genes. Myopic right-handers got married, both are diheterozygotes. Determine the possible genotypes and phenotypes of the offspring. What is the probability of having myopic children?

Let’s designate the gene that causes the development of myopia in humans as B, then the gene for normal vision will be designated as b.

Let’s designate the gene for right-handedness as P, then the gene for left-handedness will be p.

Diheterozygous short-sighted right-handers, according to the designation, will be BbPp. They will produce four types of eggs and sperm – bp, BP, BP, bP.

In this family, the probable offspring are represented by the following options:

short-sighted children, wielding mainly the right hand (BBPP, 2BbPP, 2BBPp, 4BbPp);

short-sighted children with a predominantly left hand (2Вbрр, ВВрр);

normally seeing children who use mainly the right hand (bbРР, 2bbРр);

normally seeing children who use mainly the left hand (bbrr).

Nearsighted children: 12 genotypes out of 16, or 75%.

Answer: 75%.