Question

Your answers to the questions these people are asking must be supported by explanations and work in the form of Punnett Squares. Don't forget that Rh factor is controlled by a separate gene from the ABO gene; you must show work for both genes. To answer the last part of #3 you will have to do some internet research on Rh disease.

1. I think I’m adopted. My blood type is different from both of my parents’ blood types, and different from my two brothers’ as well. My blood type is B-positive. My mother is Type O-negative, and my father is type A-positive. My brothers are A-negative and O-positive. Can I possibly really be part of this family?
2. I work in a hospital, and I just noticed something kind of strange about the family of a woman who just had her fourth child. None of the children have the same blood types as their parents! The mother has blood type B. Her husband has blood type A. Not a single one of their children has blood type A or B! Can this be possible?
3. I just got married and am curious about blood types for my children. My blood type is Type O-positive. My Dad has blood type A-negative. My new husband’s is type B-positive. Can you tell me what the chance is that I’d have a baby with my Dad’s blood type? Oh, and could you tell me whether I need to worry about Rh disease, as my husband and I have different Rh factors?
4. I’m contacting you anonymously, for reasons which will become obvious as you read this. I just had a baby, and there are several guys who could possibly be her father. I know it has to be one of these four, but frankly, don’t know which. I’m hoping you can help me narrow things down. So here’s the situation. I’m blood type A-negative. My baby is type O-positive. The four guys (not their real names, of course) are “Tom” (O-positive), “Bill” (B-positive), “Jim” (AB-positive) and “Clarence” (B-negative). I think it has to be “Tom.” Can you help me?
   
   NOTE: For each prospective father, determine whether he is or is not a possible father for this child, and explain why, supporting your explanations with appropriate Punnett Squares.

Answer 1

A blood group contain genes either AA or AO

B blood group contain genes either BB or BO

AB blood group contain genes A and B

O blood group contain OO

Rhesus (Rh) is a dominant gene Let us consider it contain gene + with genotype +/+ or +/- and recessive gene is - with genotype -/-.

1) There is no possibility of the person of blood type B positive to be child of mother is Type O-negative, and father is type A-positive because in both the parents there are no b genes. so his adopted person.

2) The mother has blood type B. Her husband has blood type A. Not a single one of their children has blood type A or B. Yes it is possible if the mother genotype is BB and father genotype is AA.

3) The chance is that having baby with her Dad’s blood type (A negative) is impossible because none of parents contain A gene, she is O positive i.e. O+/O- (because her father is negative) and her husband is B positive with genotypes B+/B+, B+O-/B+B-/B-O+.

Rhesus disease is a disease where there is incompatibility between the mother's blood type with that of foetus blood type.

Mother having Rh negative and child having Rh positive.

None of children have a possibility to have the rhesus disease because mother is heterozygous to rhesus factor and baby may have either negative or positive character.

4) Either Tom or Bill have a possibility to be father whereas Jim and Clarence do not have possibility because does not have O gene and Rhesus factor is negative respectively.