matings of the original mutant cat with true-breeding noncurl cats will produce both curl and noncurl f1 offspring if the curl allele is recessive, but only noncurl offspring if the curl allele is dominant.matings of the original mutant cat with true-breeding noncurl cats will produce both curl and noncurl f1 offspring if the curl allele is dominant, but only noncurl offspring if the curl allele is recessive.the allele can only be determined by methods of molecular genetics.matings of the original mutant cat with true-breeding noncurl cats will produce only curl f1 offspring if the curl allele is dominant, but both curl and noncurl offspring if the curl allele is recessive.