Question

If both parents have B blood groups (both are heterozygous), the expected blood groups in their children.

• A. B, O
• B. A, AB
• C. B only
• D. B, AB

Hint:

Remember the ABO blood group inheritance patterns: \textbf{Alleles:} I\textsuperscript{A}, I\textsuperscript{B}, i I\textsuperscript{A} and I\textsuperscript{B} are codominant. i is recessive to both I\textsuperscript{A} and I\textsuperscript{B}. \textbf{Genotypes and Phenotypes:} I\textsuperscript{A}I\textsuperscript{A} or I\textsuperscript{A}i = Blood Group A I\textsuperscript{B}I\textsuperscript{B} or I\textsuperscript{B}i = Blood Group B I\textsuperscript{A}I\textsuperscript{B} = Blood Group AB ii = Blood Group O For two heterozygous B parents (I\textsuperscript{B}i x I\textsuperscript{B}i), the offspring genotypes are 1 I\textsuperscript{B}I\textsuperscript{B} : 2 I\textsuperscript{B}i : 1 ii, leading to phenotypes B and O.

Answer 1

The Correct Option is A

Step 1: Understand the genotype of the parents.
If both parents have blood group B and are heterozygous, their genotype is \( I^B I^O \). Step 2: Perform the cross: \[ \begin{array}{c|cc} & I^B & I^O
\hline I^B & I^B I^B & I^B I^O
I^O & I^B I^O & I^O I^O
\end{array} \] Step 3: Determine the phenotypes:
\( I^B I^B \): Blood group B
\( I^B I^O \): Blood group B
\( I^O I^O \): Blood group O
So, children can have either blood group B or O.