Question

Sarah has type A blood, and Jesse has type O blood. Their son has type B blood. Can Jesse be the baby daddy? He is a bit worried. Please complete the Punnett squares to determine the possibilities. a No, type B blood must be homozygous b No, this is impossible c Yes, if both parents are heterozygous d Yes, if one parent is heterozygous

Answer 1

To determine whether Jesse can be the father of a child with type B blood when Sarah has type A blood and Jesse has type O blood, we will analyze the potential genotypes of each parent.

### Blood Type Genetics Overview:
1. **Type A blood** can have two possible genotypes:
- AA (homozygous)
- AO (heterozygous)

2. **Type O blood** has only one possible genotype:
- OO (homozygous)

3. **Type B blood** can also have two possible genotypes:
- BB (homozygous)
- BO (heterozygous)

### Genotype Analysis:
- **Sarah (type A)**:
- Could be AA or AO.

- **Jesse (type O)**:
- Must be OO.

We can create Punnett squares based on these possible combinations:

### Case 1: Sarah is AA
| | A | A |
|------|-----|-----|
| O | AO | AO |
| O | AO | AO |

- If Sarah is AA, all children would have genotype AO (type A). **Type B blood would not be possible**.

### Case 2: Sarah is AO
| | A | O |
|------|-----|-----|
| O | AO | OO |
| O | AO | OO |

- If Sarah is AO, the children could have:
- AO (type A)
- OO (type O)

**Type B blood still would not be possible**.

### Conclusion:
Since Sarah (type A) cannot produce a child with type B blood when paired with Jesse (type O), Jesse cannot be the father if the child has type B blood.

The correct option is:
**b No, this is impossible**.