A man expresses a certain X-linked recessive genetic disorder. Which of the following must be true?
Correct answer: C. His mother passed on the allele for the disorder
- A. His mother expresses the disorder
- B. His father passed on the allele for the disorder
- C. His mother passed on the allele for the disorder
- D. None of these options is correct
Explanation
An X-linked disease can only be passed from father to daughter, so option C is most likely the correct option. An affected man would not have got the allele from his father.
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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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