What is the genotype and phenotype of the parents?

Tt and normal -choices a and e can be ruled out at once, since they offer the dominant homozygous choice e or heterozygous genotype paired with a recessive phenotypethis is clearly impossible. choice c may also be eliminated, as all offspring from a tt x tt cross would be phenotypically recessive. the phenotypic ratio for the f1 is 735:265 for normal:twisted ears, or about 3:1. a 3:1 phenotypic ratio is associated with a 1:2:1 genotypic ratio, and both ratios will result from a crossing of heterozygotes parents, in this case, tt x tt. a punnett square solution will verify this conclusion.