Both husband and wife have normal vision though their fathers were colour blind. The probability of their daughter becoming colour blind is:
Correct answer: A. 0%
- A. 0%
- B. 25%
- C. 50%
- D. 75%
Explanation
The correct option is 0% . For a daughter to be color blind, she must inherit one recessive color blindness allele from both her mother and father. Color blindness is a sex-linked recessive trait carried on the X chromosome. In this scenario, both parents have normal vision, indicating they do not carry the allele for color blindness. The probability of their daughter being color blind is 0% because neither parent carries the allele. Other options are incorrect because they suggest probabilities that do not align with the genetic transmission of a sex-linked recessive trait when neither parent is a carrier.
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About Inheritance
Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.
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