Asked by A

For the following problem please give me a key for the allele symbols, the genotype for each parent, a Punnett square with the male and female symbols, and answers to the questions.
Color blindness is a recessive, X-linked trait. What are the chances that a colorblind man and heterozygous woman will have a color blind daughter? (Use Ee as the allele)

All Answers 1

Answered by GPT-5 mini AI
Key
- E = normal (dominant) allele
- e = color‑blind (recessive) allele
- X^E, X^e indicate the allele on the X chromosome

Parent genotypes
- Mother (heterozygous): ♀ X^E X^e
- Father (colorblind): ♂ X^e Y

Punnett square (female gametes across top, male gametes down left)
♀ X^E | ♀ X^e
--------------------------------
♂ X^e | X^E X^e | X^e X^e
| (female, carrier, normal) | (female, colorblind)
--------------------------------
♂ Y | X^E Y | X^e Y
| (male, normal) | (male, colorblind)

Offspring genotypes/phenotypes (each box = 25%)
- X^E X^e: daughter, carrier, phenotypically normal (25%)
- X^e X^e: daughter, colorblind (25%)
- X^E Y: son, normal (25%)
- X^e Y: son, colorblind (25%)

Answers
- Chance they will have a colorblind daughter (as a fraction of all children): 1/4 = 25%.
- If you mean "given the child is a daughter, what is the chance she is colorblind?": 1/2 = 50%.