Question

in humans, hemophilia is a sex linked trait. females can be normal, carriers, or have the disease. males will either have the disease or not (but they wont ever be carriers)
$x^h x^h$ = female, normal
$x^h y$ = male, normal
$x^h x^h$ = female, carrier
$x^h y$ = male, hemophiliac
$x^h x^h$ = female, hemophiliac
show the cross of a man who has hemophilia with a woman who is a carrier

Explanation:

Step1: Determine Genotypes

Man with hemophilia: \(X^hY\) (he contributes \(X^h\) or \(Y\)).
Woman (carrier): \(X^HX^h\) (she contributes \(X^H\) or \(X^h\)).

Step2: Set Up Punnett Square

	\(X^h\) (from man)	\(Y\) (from man)
\(X^h\) (from woman)	\(X^hX^h\) (female, hemophiliac)	\(X^hY\) (male, hemophiliac)

Step3: Analyze Offspring

• Female offspring: \(X^HX^h\) (carrier, 50%) and \(X^hX^h\) (hemophiliac, 50%).
• Male offspring: \(X^HY\) (normal, 50%) and \(X^hY\) (hemophiliac, 50%).

Answer:

Punnett Square:

	\(X^h\)	\(Y\)
\(X^h\)	\(X^hX^h\)	\(X^hY\)

Offspring ratios:

• 25% female carrier (\(X^HX^h\)), 25% female hemophiliac (\(X^hX^h\)),
• 25% male normal (\(X^HY\)), 25% male hemophiliac (\(X^hY\)).