In cocker spaniels the allele for a black coat color (B) is dominant over the allele for a brown coat color (b). If a brown cocker spaniel is crossed with a het erozygous black cocker spaniel which of the following genotypic ratios can be expected? 1BB:2Bb:1bb 2BB:0Bb:2bb 0BB:2Bb:2bb 2BB:1Bb:0bb

To determine the genotypic ratio of the offspring from crossing a brown cocker spaniel with a heterozygous black cocker spaniel, we need to consider the alleles involved.<br /><br />Given information:<br />- for a black coat color (B) is dominant over the allele for a brown coat color (b).<br />- A brown cocker spaniel has the genotype bb.<br />- A heterozygous black cocker spaniel has the genotype Bb.<br /><br />When crossing a brown cocker spaniel (bb) with a heterozygous black cocker spaniel (Bb), the possible genotypes of the offspring can be determined using a Punnett square.<br /><br />Punnett square:<br />```<br /> B b<br /> +------+------+<br />b | Bb | bb |<br /> +------+------+<br />b | Bb | bb |<br /> +------+------+<br />```<br /><br />From the Punnett square, we can see that the possible genotypes of the offspring are:<br />- 2 Bb (heterozygous black)<br />- 2 bb (brown)<br /><br />Therefore, the correct genotypic ratio that can be expected is:<br />$0BB:2Bb:2bb$<br /><br />So, the correct answer is:<br />$0BB:2Bb:2bb$