Question 4
Once again, because type O blood results from the homozygous recessive genotype (i i ), the only way to produce a type O child is if both parents provide an O allele (i ).
Since the father has blood type B, he must be heterozygous (IB i ).
Because the mother has blood type O, she must be homozygous for the O allele (i i ).
Construct a Punnett square diagram to determine the possible offspring of these two parents:
Based upon these results, we can see that these parents may produce offspring with the following blood type phenotypes: B and O, each with a 50% chance of occurring in their next child.
It would be impossible to produce children with either type A or type AB blood. In such a situation, the mother could be in a lot of trouble!
J