In humans blue eye colour is recessive to brown eye colour. If a boy has brown eyes and mother blue-eyed, what would be phenotype of father ?

Options

A. Green eye
B. Blue eye
C. Black eye
D. Brown eye

Answer

To solve the question about the eye color inheritance in humans, we need to analyze the genetic information provided.

### Step-by-Step Solution:

1. **Understanding Eye Color Genetics**:
- In humans, brown eye color (B) is dominant over blue eye color (b). This means that a person with at least one B allele will have brown eyes, while a person with two b alleles will have blue eyes.

2. **Identifying the Mother's Genotype**:
- The mother has blue eyes, which means her genotype must be homozygous recessive (bb).

3. **Identifying the Son's Phenotype**:
- The son has brown eyes. Since brown is dominant, his genotype must include at least one dominant allele (B). Therefore, he could either be homozygous (BB) or heterozygous (Bb). However, since his mother can only contribute a recessive allele (b), the son must be heterozygous (Bb).

4. **Determining the Father's Contribution**:
- Since the son is Bb (brown eyes), he inherited the B allele from his father. This means the father must have at least one B allele.

5. **Father's Possible Genotype**:
- The father can either be homozygous dominant (BB) or heterozygous (Bb). In both cases, the father will have brown eyes.

6. **Conclusion**:
- Therefore, the phenotype of the father must be brown-eyed.

### Final Answer:
The phenotype of the father is brown-eyed.

---