Haemophilia is more commonly seen in human males than in human females because:
Correct answer: B. This disease is due to a X-linked recessive mutation.
- A. A greater proportion of girls die in infancy.
- B. This disease is due to a X-linked recessive mutation.
- C. This disease is due to a Y-linked recessive mutation.
- D. This disease is due to an X-linked dominant mutation.
Explanation
Hemophilia is more commonly observed in human males than in human females because it is caused by a recessive mutation on the X chromosome. Males, having only one X chromosome, are more likely to express the disease if they inherit the mutant allele, while females need two copies of the mutant allele to manifest the condition. This difference in chromosome composition explains the higher prevalence of hemophilia in males.
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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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