Amouse from a true-breeding population with normal gait was crossed to a mouse displaying an odd gait called "dancing." the f1 animals all showed normal gait. a. if dancing is caused by homozygosity for the recessive allele of a single gene, what proportion of the f2 mice should be dancers? b. if mice must be homozygous for recessive alleles of both of two different genes to have the dancing phenotype, what proportion of the f2 should be dancers if the two genes are unlinked? c. when the f2 mice were obtained, 42 normal and 8 dancers were seen. use the chi-square test to determine if these results better fit the one-gene model from part a or the two-gene model from part b.