Question map
Which one of the following are the possible blood groups of the offspring of the parents with blood group 0 and AB?
Explanation
The inheritance of ABO blood groups is determined by three alleles: IA, IB, and i. Blood group O is a recessive trait, meaning a person with blood group O must have the genotype 'ii' [t2][t7]. Blood group AB is a result of codominance, where both A and B antigens are expressed, resulting in the genotype 'IAIB' [t1][t6]. When a parent with group O (ii) and a parent with group AB (IAIB) have offspring, the O parent can only contribute the 'i' allele, while the AB parent can contribute either the 'IA' or 'IB' allele [t3]. Using a Punnett square, the possible genotypes for the offspring are 'IAi' (Type A) and 'IBi' (Type B) [t2][t4]. Consequently, the children can only have blood group A or B; they cannot have group O (which requires an 'i' from both parents) or group AB (which requires both 'IA' and 'IB' alleles) [t2][t5].
Sources
- [1] https://www.britannica.com/video/ABO-blood-types-Punnett-square-blood-group-inheritance/-245082
- [2] https://www.ncbi.nlm.nih.gov/books/NBK2267/