An Rh- woman is married to Rh+ man whose father was Rh-.The risks of Erythroblastosis fetalis baby can be:
Correct answer: B. 1 : 1
- A. 3 : 1
- B. 1 : 1
- C. 2 : 1
- D. All
Explanation
The risk of erythroblastosis fetalis, also known as hemolytic disease of the newborn, occurs when an Rh-negative mother carries an Rh-positive fetus. In this case, if the father is Rh-positive and his father was Rh-negative, there is a chance that the father inherited the Rh-positive allele from his mother and is heterozygous. This means there is a 50% or 1;1 chance that he could pass on the Rh-negative allele to his offspring. Therefore, the risk of erythroblastosis fetalis in their babies would depend on the father's specific genotype, and genetic counseling may be advisable to determine the exact risk.
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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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