Ben has hemophilia His parents are both normal for blood clo

Ben has hemophilia. His parents are both normal for blood clotting. In his family history, he knows that his grandfather and great uncle on his mother\'s side are both hemophiliacs. None of his female relatives are known to have hemophilia. (a) What is the mode of inheritance for hemophilia? ________ (b) What is Ben\'s mother\'s genotype? ________ (c) What is Ben\'s father s genotype?________ (d) Ben\'s sister has normal blood clotting. What is the chance that she is a carrier? ________ (e) If Ben marries Claire, who has normal blood clotting but whose father is a hemophiliac, what are the expected phenotypic and genotypic ratios of their children (state your answers as percentages of sons and daughters)? ________ (Show your work using a Punnet Square)

Solution

11.

Answer:

Ben’s genotype : XcY

(a)Hemophilia is an X linked recessive inheritance

Ben’s parents:

(b)Mother (XcX)

(c)Father (XY)

(d)½ chances

(e) XcY (ben) x Claire (XcX)

Children: XcXc, XcX, XcY, XY

50% of daughters are affected and 50% of sons are affected

XcY (ben) x Claire (XcX)

Xc

Y

Xc

XcXc

XcY

X

XcX

XY

	Xc	Y
Xc	XcXc	XcY
X	XcX	XY