Multiple alleles genetics question, 10 points for someone's good help and right answer?

Question

Four babies were mixed up in a maternity hospital, so that each parent was given the wrong child. The babies had the following blood groups: O,A, B and AB. The four sets of parents had the following blood groups :

couple no 1 father O mother O

couple no 2 father AB mother O

couple no 3 father B mother B

couple no 4 father A mother B

Which baby belongs to which parent ? Please show me how you got your answer, I missed a day of school and didn't get notes

Thanks for your help and 10 points to the person who shows me how to get the right answer

Answer 1

well hi. blood group genes are co dominantly expressed so now we can solve it

1. couple 1 both mother & father have O blood group so both of them will have OO genes coz to be of blood group O you need this set of genes. so they cannot have child of any other blood group but O so the child with O blood group is of couple no 1

3 Now for couple no 3 mother has B same as father so both of them could have genotype BO or BB so they can have child of either blood group B or O but couple one is having O child so the child with blood group B is of couple no 3

2 now couple 2 mother is O & father is AB so mom will have OO genotype & dad will have AB genotype so they can either  A or B blood group child but B blood group child is of couple 3 so couple will have A group child

the last remaining child is of couple 4!

Answer 2

Couple 1- Both parents are O i.e. genotype is OO so the baby has to be OO (since O is recessive to both A & B) Thus, blood group O baby belongs to couple 1.

Couple-2 Father is AB and mother is OO

Possible genotype of baby- AO (blood group-A) or BO (blood group-B) but their baby can't be AB.

Couple-3 Possible gentypes of parents- BB or BO

Possible genpotype of the baby- BB 25%) or BO (50%) or OO (25%). It can't be OO because that has to be couple-1 baby. Thus, couple-3 baby has blood group- B



P.S.- That confirms couple-2 baby has blood group-A.

Couple-4 only remaining choice- blood group- AB and that also fits into  their blood groups.

Answer 3

A and B are co-dominant, O is recessive.

so baby o has the genotype oo

baby A could have the genotype AA or Ao

baby B could have the genotype BB or Bo

baby AB has the genotype AB

with me so far? now the parents,

couple no 1: genotype: oo x oo  Result: oo (100%)

couple no 2: genotype: AB x oo  Result: Ao or Bo (50-50%)

couple no 3: genotype: (BB or Bo) x (BB or Bo)  Result: BB or oo (50-50%)

couple no 4: genotype: could be either (AA or Ao) x (BB or Bo) so the result could be any of the babies (coz you can get Ao, Bo, AB or oo)

still there? get it so far? couple 4 is a bit tricky so do 4 punnet squares (ie the 4 different combinations). be careful!

next part is a bit of logic....

couple no 1 : baby o (no other choice right?)

couple no 3: baby B (coz baby o is already taken)

couple no 2: baby A (coz couple 3 has baby b already k?)

which leaves couple no 4 with baby AB.

yeah, that should be right. hehe... hope this helped and your not too confused!

Answer 4

1. father and mother had to have the O baby since o is recessive both parents had to contribute the o gene

3. where father is B and mother is B. they both could have been homozyous dominant for B or heterozygous and been BO  they both contributed the B gene so their child is B

couple number 2 where  father is AB and mother OO father gave the A gene and mother the O so the child is a blood type A

couple number 4 where father is A and mother B -father contributes the A gene the mother the B gene child is AB

2. couple