Question

1. x - linked hypophosphatemia is an inherited form of rickets, a condition that results in weak or soft bones. cross a male with hypophosphatemia with an unaffected, x - linked alleles woman.

a. what’s the probability they would have a child that has hypophosphatemia? ___%

Explanation:

Step1: Determine Genotypes

Let the allele for hypophosphatemia be \( X^H \) (dominant, since it's X - linked and the male has it, and the woman is unaffected). The male with hypophosphatemia has genotype \( X^H Y \). The unaffected woman has genotype \( X^h X^h \) (homozygous recessive for the normal allele).

Step2: Set Up Punnett Square

The male can produce gametes \( X^H \) and \( Y \). The female can only produce gametes \( X^h \).

	\( X^h \)	\( X^h \)
\( Y \)	\( X^h Y \)	\( X^h Y \)

Step3: Analyze Offspring Genotypes

• Female offspring: \( X^H X^h \) (has hypophosphatemia, since the dominant allele is present).
• Male offspring: \( X^h Y \) (does not have hypophosphatemia, since the recessive normal allele is on the X - chromosome and the Y has no allele for this trait).

Out of 4 possible offspring (2 female, 2 male), 2 have hypophosphatemia (\( X^H X^h \) females).

Step4: Calculate Probability

Probability \(=\frac{\text{Number of affected offspring}}{\text{Total number of offspring}}\times100=\frac{2}{4}\times100 = 50\%\)

Answer:

50