Ms. Pratt is claiming that Mr. X is the father of her child. Ms. Pratt is O-. Her baby boy is A+. Mr. X is blood type B+. Could he be the father of her child? If not, what blood type would he be expected to be?

Question

Ms. Pratt is claiming that Mr. X is the father of her child. Ms. Pratt is O-.  Her baby boy is A+.  Mr. X is blood type B+.  Could he be the father of her child?  If not, what blood type would he be expected to be?

Mason Anderson · Accepted Answer

Nope....
BTW, I take it you meant "If so, what blood type...".
If he isn't the father, there's nothing you can say about his blood group). If he WAS the father, the child's bloodtype would be either #O^+# or #B^+#.

There are four primary blood types (eight if the Rhesus factor is taken into account). Antigens and antibodies are the key factors. Blood type A is characterized by anti-B-type antibodies in the serum and A-type antigens on the erythrocytes; The erythrocytes of blood type B have B-type antigens, and the serum contains anti-A-type antibodies; Antigens are not present in blood type O erythrocytes, but anti-A and anti-B antibodies are present in the plasma. The following combinations and outcomes pertain to pregnancy's effects: #O and O rarr O# #O and A rarr O or A# #color(red)"O and B " rarr color(red)" O or B"# #O and AB rarr A or B# #A and A rarr O or A# #A and B rarr O or A or B or AB# #A and AB rarr A or B or AB# #B and B rarr O or B# #B and AB rarr B or A or AB# #AB and AB rarr A or B or AB# Consequently, Mr. X cannot be the father if the child has blood type A. The Rhesus factor is a bit more complicated, as it actually involves around 50 different factors, but suffice to say that, if one of the parents is #Rh^+#(positive), the child will be, no matter whether the other parent is #Rh^+# or #Rh^-#... Therefore, if mr. X would be that father, the child would have either #O^+# or #B^+#...

Kai Andersen · Answer

undefined No, Mr. X cannot be the father of Ms. Pratt's child. Since Ms. Pratt is O- and her baby is A+, Mr. X would need to have either blood type A or AB to be the father. Therefore, Mr. X would be expected to have blood type A or AB.