In 1981, a stray black cat with unusual rounded, curled-back ears was adopted by a family in California. Hundreds of descendants of the cat have since been born, and cat fanciers hope to develop the curl cat into a show breed. Suppose you owned the first curl cat and wanted to develop a true-breeding variety. How would you determine whether the curl allele is dominant or recessive? How would you obtain true-breeding curl cats? How could you be sure they are true-breeding?

Verified step by step guidance

1. First, determine if the curl allele is dominant or recessive by breeding the original curl cat with a normal-eared cat. If any of the offspring have curled ears, the curl allele is likely dominant. If none of the offspring have curled ears, the curl allele is likely recessive.
2. To develop a true-breeding line, if the curl trait is dominant, continue to breed the curled ear cats with each other. Selectively breed those that consistently produce curled ear offspring.
3. If the curl trait is recessive, breed two cats that have curled ears together, as they would be homozygous recessive (cc). Their offspring should all have curled ears if they are true-breeding.
4. To ensure the cats are true-breeding, perform test crosses with normal-eared cats. If the offspring from these crosses all exhibit the expected phenotype (curled or normal ears based on the dominant or recessive nature of the allele), then the line can be considered true-breeding.
5. Maintain detailed breeding records including phenotypes of all offspring to monitor the inheritance pattern over several generations. This will help confirm the genetic consistency of the curled ear trait in the population.