The "B Locus" refers to a specific location on a chromosome that influences the color of an organism's coat or fur. In genetics, it is particularly important in determining the presence of black or brown pigmentation in animals, such as dogs and cats. The alleles at this locus can result in different color variations based on the combination inherited from the parents. In dogs, for example, the B Locus has two primary alleles: B (black) and b (brown). The presence of the dominant B allele typically results in a black coat, while the recessive b allele leads to a brown coat. Understanding the B Locus helps breeders and geneticists predict and select for specific coat colors in various breeds.