Both Mrs. Suarez and Mrs. Junco had babies the same day in the same hospital. Mr

Question

Both Mrs. Suarez and Mrs. Junco had babies the same day in the same hospital.
Mrs. Suarez took home a baby girl, whom she named Susan. Mrs. Junco also took
home a girl, whom she named Julie . Mrs. Junco started to suspect, however, that
the girl had been accidentally switched with Mrs. Suarez's baby in the nursery.
Blood test were made; Mr. Suarez was type A, Mrs. Suarez was type B, Mr. Junco
was type A, Mrs. Junco was type A. Susan was type O, and Julie was type B.
Were the baby girls switched? Explain your answer by showing your work.

Explanation / Answer

Lets first understand what the questions are asking. We need to know how to compute basic punnett squares. Lets look at the Suarez's. To understand the punnett square, we need to know what Type A and Type B mean. Type A means that at two loci for blood type there exist only the A antigen, meaning that the phenotype is Type A but the genotype may be either AA (both loci are the A antigen) or AO (meaning the second locus is empty). The same is true for type B, meaning the genotype of type B is either BB or BO. Now lets note that the punnett cross that gives us the most information will be the one with the greatest number of outcomes. That will be true for the case of AO x BO, so we will use that one. A O B AB BO O AO OO So the Suarez's can have kids of any blood type (O, A, B, or AB). Now lets examine the Junco's. Both parents are type A so we will examine the punnett cross of AO and AO. A O A AA AO O AO OO So the Juncos can only have kids of either type O or A. Now lets look at the babies. Julie is type B, meaning she could not have been born to the Juncos, since they cannot possibly make a type B punnett cross. Therefore, she must be a Suarez, so the babies must have been switched! What at unfortunate mix up! However, we were able to determine this based only on their blood types.

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.