An Rh−ve man marries an Rh+ve (homozygous) woman.What are the chances of their children being Rh+ve?
Correct answer: D. 100%
- A. 0%
- B. 25%
- C. 50%
- D. 100%
Explanation
The correct answer is 100%. An Rh−ve man has a genotype of 'rr', meaning he can only pass on the 'r' allele. The Rh+ve woman, being homozygous, has a genotype of 'RR' and can only pass on the 'R' allele. Therefore, all children will inherit an 'R' from the mother, resulting in an 'Rr' genotype. This means all children will be Rh+ve. The other options are incorrect because they do not account for the homozygous nature of the mother's genotype, which guarantees that all offspring will inherit the Rh+ allele.
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About Mendel's Laws of Inheritance
Mendelian inheritance explains how alleles separate into gametes and assort during reproduction, producing predictable genotype and phenotype ratios. Questions cover dominance, recessiveness, homozygous and heterozygous conditions, the laws of segregation and independent assortment, monohybrid and dihybrid crosses, test crosses and the limits caused by linked genes.
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