Question

1. a person with blood type b has a child with a person whose blood type is b. their child has type o blood. what are the genotypes of the parents?

a $i^b i$ and $i^b i^b$
b $i^a i$ and $i^b i$
c $i^b i$ and $i^b i$
d $i^a i^b$ and $i^b i$

Explanation:

Step1: Recall blood type genetics

Blood type O has genotype $ii$. For a child to inherit $ii$, each parent must pass an $i$ allele.

Step2: Analyze parent blood type B

Blood type B can have genotypes $I^BI^B$ or $I^Bi$. Since each parent must contribute an $i$ allele, neither parent can be $I^BI^B$.

Step3: Match to options

Both parents must be $I^Bi$ to have a type B phenotype and pass $i$ alleles to their child.

Answer:

C. $I^Bi$ and $I^Bi$