Hemophilia was common during the 1800s in the royal families of Europe, whose members often intermarried. Queen Victoria of England was a carrier of the trait. She had one X chromosome with the allele for normal blood clotting (XH) and the other with the defective allele (Xh). Because she did have one normal dominant allele, her blood clotted normally. Her husband, Prince Albert, was completely normal for this trait. He had one normal allele on the X chromosome (XH) and a Y chromosome with no allele related to blood clotting (Yo). Eighteen of Queen Victoria’s 69 descendants were carrier females or hemophiliac males. Crown Prince Alexis of Russia was one of these hemophiliac descendants. His affliction indirectly contributed to the overthrow of the monarchy in Russia. What would the ratio of phenotypes of Victoria and Albert children be?
