Mr. jones has blood type b and mrs. jones has blood type ab. what is the probability that they will have a child with blood type a if both of mr. jones’s parents were ab?
a. 0%.
b. 25%.
c. 50%.
d. 100%.

The correct answer would be a. 0%

Mr. Jones has blood group B and that of their parents was AB. Thus, he must be homozygous for blood group B that is, .

Then, he would only produce one type of gamete, .

The blood group of Mrs. Jones is AB. Thus, the genotype of her gene would be .

Hence, she would produce two types of gametes, one containing and other containing .

The cross would result in the production of children with two types of genotypes and .

Thus, the phenotype of children can be either blood group AB or blood group B.

Hence, the probability of a child having a blood group A would be 0%.