A man having a blood group O marries a woman having a blood group A whose father was also O. What is the probability of 'O' in their offspring?

Explanation

option A is correct. The probability of having blood group O in their offspring is 50%. The ABO blood group system is determined by the presence of three different alleles of the ABO gene: A, B, and O. The A allele is responsible for the production of the A antigen, the B allele is responsible for the production of the B antigen, and the O allele is responsible for the production of neither antigen. If a man has type O blood, he must have two O alleles. This means that the man can only pass down an O allele to his offspring. If a woman has type A blood, she could have either one A allele and one O allele (genotype AO) or two A alleles (genotype AA). If the woman's father was also type O, then she must have inherited one O allele from him. This means that the woman could only pass down an A allele or an O allele to her offspring. The probability of the offspring having type O blood is 50%. This is because there is a 50% chance that the offspring will inherit two O alleles from the father and a 50% chance that the offspring will inherit one O allele and one A allele from the mother. The probability of the offspring having type A blood is 50%. This is because there is a 50% chance that the offspring will inherit one A allele from the mother and one O allele from the father and a 50% chance that the offspring will inherit two A alleles from the mother. The probability of the offspring having any other blood group is 0%. This is because the B allele is not present in either parent.