Body Fluids and Circulation Question 36
36. A man with blood group A marries AB blood group woman. Which type of progeny indicate that the man is not homozygous?
[1993]
(a) $AB$
(b) $B$
(c) $A$
(d) $O$
Show Answer
Answer : b
Hints & Solutions
$$ \left.\begin{array}{rl}\operatorname{Man}(\mathrm{A}): \mathrm{I}^{\mathrm{A}} \mathrm{I}^0 & \rightarrow \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{A}} \rightarrow \mathrm{A} \\ & \rightarrow \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}} \rightarrow \mathrm{AB} \\ \text { Woman }(\mathrm{AB}): \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}} & \rightarrow \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{O}} \rightarrow \mathrm{AB} \\ & \rightarrow \mathrm{I}^{\mathrm{B}} \mathrm{I}^{\mathrm{O}} \rightarrow \mathrm{B}\end{array}\right] \text {all show heterozygous} $$
OR
$$ \left.\begin{array}{rl} \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{A}} & \rightarrow \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{A}} \rightarrow \mathrm{A} \\ & \rightarrow \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}} \rightarrow \mathrm{AB} \\ \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}} & \rightarrow \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{A}} \rightarrow \mathrm{A} \\ & \rightarrow \mathrm{I}^{\mathrm{A}} \mathrm{I}^{\mathrm{B}} \rightarrow \mathrm{AB} \end{array}\right] \text { all show homozygous } $$
