The allele that causes Brachyphalangy (B) is dominant in humans and is lethal when homozygous (i.e. the person with that genotype dies). People with the recessive phenotype (bb) have normal fingers, while heterozygotes have characteristically short fingers. A separate gene influences tongue rolling; the ability to roll the tongue (R) is dominant to non-rolling (r). Two short-fingered people, one not able to roll his tongue and the other heterozygous for both these alleles, have children. What genotypic and phenotypic ratios are expected in their potential offspring?.