Question

Name

Human Blood types are determined by genes that follow the Codominance pattern of
inheritance. There are two dominant alleles A and B, and one recessive allele O.
Mother type O
Baby type A
Pharmacist type O
Waiter type B
Postman type AB
Gas Station Cashier A
9. There is a cheating scandal in your town, and as a nosey neighbor you want to investigate
who the father of the baby is. Based on the information you obtained, which man in your
town could not be the father of the baby? Circle your answer(s) and justify your answer(s)
with Punnett squares. (7 pts)
Blood Type.

Answer 1

• Pharmacist and waiter.

Step-by-step explanation:

To find:-

• Who could not be the father of the baby .

Answer:-

We are here given that the baby has a blood group of A and the mother has a blood group type of O . Now since mother is O blood group, her genotype would be ii , because the recessive alleles are only able to express themselves in homozygous condition.

Now baby has a blood group of A , so it's genotype could be
`I^AI^A` or
`I^A i` ( because A is dominant over i and is able to express itself in heterozygous condition) .

Eliminating who can't be the father of the baby:-

• Pharmacist's blood group is O , so his genotype would be again ii , so all the gametes carried in his sperm would contain the allele " i " . Same goes with the mother, her ovum would also carry i allele of the gene as she too has blood group of O . For Punnet square see attachment. From the Punnet square it's clear that the pharmacist can't be the father of the child as all the offspring produced would have O blood group .
• Secondly the blood group of the waiter is B , so his genotype could be
  `I^Bi` or
  `I^B I^B` . So the gametes produced by him would either contain the allele
  `I^B` or the allele i . So on making Punnet square we can see that all the offsprings produced would either have B blood group or O blood group. So the waiter too can't be the father of the baby .

Possible father of the baby :-

• Finally the blood groups of the postman and cashier are AB and A respectively. So their genotypes would be
  `I^BI^A` and
  `I^Ai \ / I^AI^A` respectively. As you can see both of them have the allele
  `I^A` , so both of them could be the father of the baby .