8.28 The Manx breed of cat has no tail or a very short tail. When two Manx cats are bred to each other, the litter size is reduced, some of the kittens have no tails, and some have a full-length tail. Among many such crosses, tailless offspring are about twice as common as kittens with a full tail. No true-breeding Manx cats have been found, despite more than a century of interest by cat breeders. a. Provide an explanation consistent with these data that explains why no true-breeding tailless Manx cats have been found. b. In addition to being tailless, the Manx breed is often prone to skeletal problems such as a shortened or poorly formed spinal column. Using the proper terminology, postulate an explanation for this phenotype.