Alexander's mother has the blood type BO and his father has the blood type O.

Question

Which blood type could Alexander have?

Draw a Punnett square on scratch paper to help you answer the question, if needed.

Responses

AB
uppercase A B

O
O

A
A
Phenotypes and Genotypes of Blood Types

Blood Type and Allele Possible Genotypes and Alleles
A (IA)
AA
or AO (IAIA or IAI)
B (IB)
BB
or BO (IBIB or IBI)
AB (IA IB)
AB (IA IB)
O (I)
OO (II)

Answer 1

To determine Alexander's possible blood types, let's first break down the genotypes of his parents.

• Alexander's mother has blood type BO, meaning her genotype can be either:
  • IB (for B) and I (for O)
  • or only I (for O) and IB.

Thus, her genotype is BO (IBI).

• Alexander's father has blood type O, meaning his genotype is OO (II).

Now we can set up a Punnett square to explore the possible combinations of these alleles:

      I      I
   ----------------
 IB |  IB   |  IB   |
   ----------------
 I  |   I    |   I    |

The possible combinations of alleles from the parents are:

1. From mother: IB and I
2. From father: I and I

By filling out the Punnett square, we find:

• Row 1: Child could inherit one IB from the mother and one I from the father = IB I (Blood type B)
• Row 2: Child could inherit one I from the mother and one I from the father = II (Blood type O)

Therefore, Alexander's possible blood types are:

• Blood Type B (IB I)
• Blood Type O (II)

So, Alexander could have blood type B or blood type O.