Question
A mother and father both have brown hair and eyes, while their child has brown hair and blue eyes. If brown hair and eyes are dominant traits and blonde hair and blue eyes are recessive traits, which inference can be drawn about the alleles passed to the child?
Answers
GPT-4o mini
In this scenario, we have to consider the inheritance of traits and the dominance of those traits. Brown hair and brown eyes are dominant traits, while blonde hair and blue eyes are recessive traits.
For the child to have blue eyes, they must have inherited two recessive alleles for eye color (one from each parent). Given that both parents have brown eyes, it is likely that both parents are heterozygous for the eye color trait, meaning they each carry one allele for brown eyes (dominant) and one allele for blue eyes (recessive). Therefore, their genotypes can be represented as follows:
- Parent 1: Bb (for eyes)
- Parent 2: Bb (for eyes)
In this case, the combinations of alleles from the parents could produce a child with the following possible combinations for eye color:
- BB (brown eyes)
- Bb (brown eyes)
- bB (brown eyes)
- bb (blue eyes)
Since the child has blue eyes, their genotype must be bb.
Now regarding the hair color, since the child has brown hair, and assuming both parents have brown hair, one or both parents must also carry a recessive allele for blonde hair. So we can follow a similar logic:
- It's likely that at least one, if not both, parents are heterozygous for brown hair, represented as Bb (brown hair being dominant and b representing blonde hair).
Thus, the possible combinations for hair color that could lead to a child having brown hair (B being the dominant trait) might include:
- BB (brown hair)
- Bb (brown hair)
- bB (brown hair)
In conclusion, the inference we can draw is that both parents likely carried a recessive allele for both traits. Therefore, the child received one recessive blue eye allele from each parent (bb) and likely received at least one dominant hair allele (B) from at least one parent for brown hair. Thus, the child is genotype Bb for hair color and bb for eye color.
For the child to have blue eyes, they must have inherited two recessive alleles for eye color (one from each parent). Given that both parents have brown eyes, it is likely that both parents are heterozygous for the eye color trait, meaning they each carry one allele for brown eyes (dominant) and one allele for blue eyes (recessive). Therefore, their genotypes can be represented as follows:
- Parent 1: Bb (for eyes)
- Parent 2: Bb (for eyes)
In this case, the combinations of alleles from the parents could produce a child with the following possible combinations for eye color:
- BB (brown eyes)
- Bb (brown eyes)
- bB (brown eyes)
- bb (blue eyes)
Since the child has blue eyes, their genotype must be bb.
Now regarding the hair color, since the child has brown hair, and assuming both parents have brown hair, one or both parents must also carry a recessive allele for blonde hair. So we can follow a similar logic:
- It's likely that at least one, if not both, parents are heterozygous for brown hair, represented as Bb (brown hair being dominant and b representing blonde hair).
Thus, the possible combinations for hair color that could lead to a child having brown hair (B being the dominant trait) might include:
- BB (brown hair)
- Bb (brown hair)
- bB (brown hair)
In conclusion, the inference we can draw is that both parents likely carried a recessive allele for both traits. Therefore, the child received one recessive blue eye allele from each parent (bb) and likely received at least one dominant hair allele (B) from at least one parent for brown hair. Thus, the child is genotype Bb for hair color and bb for eye color.