Question

colorblindness is a sex - linked disorder. a female (xxᵇ) is a carrier for colorblindness and her husband (xᵇy) is colorblind. use the punnett square below to answer the next question. punnett square with columns x, xᵇ and rows xᵇ, y taking into consideration all of the offspring, what is the probability that this couple will have a colorblind female? 0% (0 out of 4) 25% (1 out of 4) 50% (2 out of 4) 100% (4 out of 4)

Explanation:

Step1: Determine possible offspring genotypes

The female is \( XX^b \) (carrier) and the male is \( X^bY \) (colorblind). The Punnett square combinations are:

• Top - left: \( X \times X^b = XX^b \) (carrier female)
• Top - right: \( X^b \times X^b = X^bX^b \) (colorblind female)
• Bottom - left: \( X \times Y = XY \) (normal male)
• Bottom - right: \( X^b \times Y = X^bY \) (colorblind male)

Step2: Count total and colorblind female offspring

Total offspring genotypes: 4 ( \( XX^b \), \( X^bX^b \), \( XY \), \( X^bY \) ).
Colorblind female genotype: \( X^bX^b \) (1 out of 4).

Step3: Calculate probability

Probability \( = \frac{\text{Number of colorblind female offspring}}{\text{Total offspring}}=\frac{1}{4} = 25\% \).

Answer:

25% (1 out of 4)