Which of the following sets of children could NOT be the biological children of
ID: 53583 • Letter: W
Question
Which of the following sets of children could NOT be the biological children of a man with blood type B, M and a woman with blood type A, MN?
a child with blood type A, M and a child with blood type B, M
a child with blood type A, N and a child with blood type B, N
a child with blood type AB, M and a child with blood type AB, MN
a child with blood type O, M and a child with blood type O, MN
all of the above could be the biological children
I know how to figure out blood type, but im not sure what to do with the MN/M stuff.
Explanation / Answer
a child with blood type A, N and a child with blood type B, N
When the blood group of man is type B (IBIO or IBIB) and blood group of woman is type A (IAIO or IAIA) the possible blood types inherited in their children can be represented in Punnet’s square 1 below:
Gametes
IB
Io
IA
IAIB (Type AB)
IAIO (Type A)
IO
IBIO (Type B)
IOIO (Type O)
When the blood group of man is M (MM- homozygous) and blood group of woman is type MN (MN- heterozygous) the possible blood types inherited by their children can be represented in Punnet’s square 2 below:
Gametes
M
M
M
MM (Type M)
MM (Type M)
N
MN (Type MN)
MN (Type MN)
By consolidating the data from Punnet’s square 1 and 2 we can observe that there is no possibility of inheriting N type blood in children of a man with blood type B, M and a woman with blood type A, MN.
Hence we can conclude that the a child with blood type A, N and a child with blood type B, N could NOT be the biological children of a man with blood type B, M and a woman with blood type A, MN.
Gametes
IB
Io
IA
IAIB (Type AB)
IAIO (Type A)
IO
IBIO (Type B)
IOIO (Type O)