"Chromosomes are paired, one pair determines sex, two 'X' chromosomes is female and one-X one-'Y' is male, bleeding-easily would be carried on an X-chromosome, but suppressed by the other X-chromosome of the pair if there's two Xs, and express itself when there's one X and one Y, so it'll skip his sons and their sons and show up in half the daughter's grandsons - I'll explain this later, but it's not complicated once you know what's going on and can see it under a microscope."

"Chromosomes are paired, one of the 23 pairs determines sex, two 'X' chromosomes is female and one-X one-'Y' is male, bleeding-easily would be carried on an X-chromosome, but suppressed by the other X-chromosome of the pair if there's two Xs, and express itself when there's one X and one Y, so it'll skip his sons and their sons and show up in half the daughter's grandsons - I'll explain this later, but it's not complicated once you know what's going on and can see it under a microscope."