The allele for black coat is recessive to the allele for white/pink coat.
The correct answer and explanation is:
In this scenario, the allele for a black coat is recessive to the allele for a white or pink coat. This means that for an individual to express the black coat color, it must have two copies of the black coat allele, one from each parent.
In genetics, alleles are alternative versions of a gene that can produce different traits. When two alleles for a gene are different, the dominant allele will typically determine the organism’s trait. In this case, the white or pink coat allele is dominant, and the black coat allele is recessive. This implies that an organism with at least one copy of the white or pink coat allele will show that coat color, while the black coat color will only appear if the individual has two recessive black coat alleles.
To further explain, let’s use the symbols “B” and “b” for the alleles where “B” represents the dominant allele for a white or pink coat, and “b” represents the recessive allele for a black coat. A white/pink-coated individual could have either the genotype “BB” (homozygous dominant) or “Bb” (heterozygous). Only an individual with the genotype “bb” will have a black coat.
When two individuals are crossed, the potential offspring genotypes can be predicted using a Punnett square. For instance, if one parent is heterozygous (Bb) and the other is also heterozygous (Bb), the resulting offspring would have the following genotype probabilities:
- 25% BB (white/pink coat)
- 50% Bb (white/pink coat)
- 25% bb (black coat)
This illustrates how the inheritance of coat color follows Mendelian genetics, with the recessive black coat color only being expressed when both alleles are recessive.