Interestingly, even though hemophilia in the royal families began in England, they were actually the only one of these four families to NOT be affected by it. If Alice's daughter Alix had accepted a marriage proposal from George V, this may have changed history greatly. If we were to rewrite history, pairing Alix and George V together, what is the probability any of their offspring would have hemophilia?

Explanation:

Hemophilia is an inherited disease and it follows  an X-linked recessive pattern. The genes for hemophilia disease are located on the X chromosome. In males one mutated copy of the chromosome X  is sufficient to cause the condition, because male contain only one gene. Female  contain XX chromosome, so both the chromosome must have mutated for causing this disease.

According to  study of  Queen Victoria (1891-1901) of England, Alice's daughter Alix was X linked carrier and George V was normal male,

so if they got married, their children would be  

parents genotype  X X*   XY

progeny  

XX, XY, X*X, X*Y

50% males would be  infected

50% male normal

50% female normal,

50 female carrier.

answer: 4

explanation: 8