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Use factorial analysis to show the percentage of phenotype and genotype of offspring suffering from the disease if a heterozygous carrier female was married to a male suffering from color blindness. Note that color blindness is a sex-linked disease. Reminder you need to use XX and XY in your answer.

A) True
B) False

User Turkinator
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Final answer:

In a cross between a heterozygous carrier female for color blindness (X/Xc) and a color blind male (XcY), there is a 50% chance their male offspring will be color blind and a 50% chance their female offspring will be carriers. No daughter will suffer from color blindness phenotypically. This occurs because color blindness is an X-linked recessive trait predominantly affecting males.

Step-by-step explanation:

To analyze the phenotype and genotype percentages of offspring from a cross between a heterozygous carrier female for color blindness and a color blind male, we need to use a Punnett square to predict the genetic outcomes. We denote the normal vision allele as 'X' and the color blindness allele as 'Xc'. The female is represented as X/Xc (heterozygous carrier), and the male, who is suffering from color blindness, is represented as XcY. The Punnett square will look like this:




  • Father's alleles: Xc, Y

  • Mother's alleles: X, Xc



When we cross these, we get the following genotype combinations:




  • X Xc (Carrier female)

  • XX (Normal vision female)

  • Xc Y (Color blind male)

  • XY (Normal vision male)



Based on these combinations, we can determine the phenotype percentages:




  • 50% chance of male offspring being color blind

  • 50% chance of male offspring having normal vision

  • 50% chance of female offspring being carriers

  • 50% chance of female offspring having normal vision



This implies that there is a 50% chance that a son will suffer from color blindness, while there is a 0% chance for a daughter to suffer from color blindness, but a 50% chance she will be a carrier of the gene like her mother.

User BorisD
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