Question

Last Sunday night at the local hospital was really busy, and the folks in the maternity ward got just a little bit flustered. Two pairs of twins were born that night within a few moments of each other, but somehow the staff forgot to put name tags on the babies, and now they don't know which babies belong to which parents. You need to help them out by analyzing the blood types of these four babies and the two couples who are anxiously waiting to take their new families home with them.

Here's what you know:

You know about the inheritance patterns of human ABO blood types

You know the blood types of the two sets of parents:

Mrs. Smith is blood type A, and her husband is blood type B.

Mrs. Abernathy is blood type O and her husband is blood type AB.

And you know the blood types of the four babies (all little girls, incidentally):

Baby #1 is blood type O

Baby #2 is blood type A

Baby #3 is blood type B

Baby #4 is blood type AB

What could be simpler? On the answer sheet, tell me which two babies you're going to send home with Mr. and Mrs. Smith, and which you are going to send with Mr. and Mrs. Abernathy. (Please identify the babies by their numbers, shown above.) Then explainexactly how you figured it out. Show work as needed for your explanation, including Punnett squares for each of these couples.

Answer 1

• Blood group genetics says as...........
• A+A------->A
• A+O------------>A
• A+B----------->AB
• B+B------->B
• B+O------------>B
• O+O----------->O
• Mrs. Smith is blood type A, and her husband is blood type B.
• Then Mrs smith has-------> either AA/AO group
• Mrs smith husband has-----> either BB/BO group
• Then their child might has any------------->AA or AB or BB or OO group; otherwise A group, B group, AB group and O group
• Mrs. Abernathy is blood type O and her husband is blood type AB.
• Then Mrs. Abernathy has-----------> OO group
• Her husband has ------------>AB group
• Then their child had-------------->AO or BO group ; otherwise A group and B group
• And you know the blood types of the four babies (all little girls, incidentally):
• Baby #1 is blood type O
• Baby #2 is blood type A
• Baby #3 is blood type B
• Baby #4 is blood type AB
• OO group is observed only in Mrs. smith family, so baby 1 belong to Mrs. smith family
• AB group is also observed only in Mrs. smith family, so baby 4 also belong to Mrs Smith
• Then baby 2 and 3 belong to Mrs. Abernathy.