question_answer 17)

A man with blood group ‘A’ married 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:

This shows that blood group 'O' is dominant and 'A' is recessive because blood group 'O' was able to express itself in heterozygous condition, due to which the progeny had blood group 'O'.