A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Answer:
The information is not sufficient to conclude which is the dominant and recessive trait.
- The genotype and the genotypic ratio is required to determine if the emergent trait is dominant or recessive.
- The genotypes using which blood group is denoted are as follows:
But according to blood heredity, the Blood type A allele is always dominant and the allele for Blood type O is always recessive .
- From the chart, blood group A can be denoted as I A I A or I A l where I A is the dominant trait and i is the recessive trait.
- Blood group O is denoted by ii (recessive allele).
