The marriage was entered into by a blue-eyed right-hander with dark hair color, heterozygous for the last two traits, and a brown-eyed right-hander with light hair, heterozygous for the first two traits. What is the probability of the birth of a blue-eyed child with a left-hander with light hair color in this family if blue eyes are left-handed and blonde hair is recessive traits. (polyhybrid crossing?
Let’s designate the gene for blue eyes of a person as in, then the gene for brown eyes will be B.
Let us designate the gene for left-handedness as c, then the gene for the predominant possession of a person with the right hand will be C.
Let’s designate the gene that determines the development of light-colored hair as e, then the gene for dark hair will be E.
A blue-eyed right-hander with dark hair, who, according to the condition, is heterozygous for the last two traits – bbCcEe. It produces the following types of sperm:
bCE, bse, bCe, bce.
Brown-eyed right-hander with light hair, heterozygous for the first two traits – ВbСсе. It produces eggs of the following types: BC e, bce, bCe, All.
All possible offspring of this married couple will look like this:
brown-eyed right-haired dark-haired children (ВbССЕе, 2ВbСсЕе);
brown-eyed right-haired fair-haired children (BbSee, BbCEE);
brown-eyed, left-haired, dark-haired children (2BbccEe);
blue-eyed right-haired dark-haired children (2bbCCEE, bbCCEE);
blue-eyed, left-handed, fair-haired children (bbssee);
blue-eyed right-handed fair-haired children (2bbCee, bbCee);
blue-eyed, left-haired, dark-haired children (bbccEe);
brown-eyed, left-handed, fair-haired children (Вbсее).
Probability of having a blue-eyed left-hander with blond hair: 1 genotype in 16, or 6.25%.