WAEC Biology 2015 Papers

Concept:When one parent's trait appears in all $F_1$ offspring, that trait is dominant and the hidden trait is recessive.Explanation:In the cross, a black-coated parent is crossed with a spotted-coated parent.All the $F_1$ offspring show the black coat.This means the black coat allele is expressed, while the spotted coat allele is suppressed.The allele that is suppressed is recessive.Therefore, the gene for the spotted coat is recessive to the gene for the black coat.The other options are incorrect because no co-dominance or homozygous dominant $F_1$ genotype is indicated.Answer:A. The gene for the spotted coat is recessive to the gene for the black coat.