A man with normal vision married a color blind woman (the recessive gene d is linked to the X chromosome). Determine the parental genotypes, the ratio of phenotypes and genotypes in the offspring.
1) Genotypes of parents: mother – ХdХd, father ХDY;
2) offspring genotypes: all daughters are carriers of the gene for color blindness – ХDХd, all sons – color blind – Хd Y;
3) the ratio of sick and healthy children is 1: 1 or 50%: 50%.
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