- Exercise 8 Who Is The Father Of These Kittens Note All Of The Kittens Have The Same Father How Do You Know This 1 (124.17 KiB) Viewed 16 times
- Exercise 8 Who Is The Father Of These Kittens Note All Of The Kittens Have The Same Father How Do You Know This 2 (134.58 KiB) Viewed 16 times
- How do you know this? Be sure to provide evidence from thescenario and from what you know about patterns of inheritance.
- Why does only one kitten have the unusual tortoiseshell coat?Be sure to provide evidence from the scenario and what you knowabout patterns of inheritance.
Work in a small group or alone to solve this "mat- ing mystery." Then answer the questions that follow. Mister Poppleton, a cat enthusiast who breeds. cats and competes on the Cat Fancier's Associ- ation competitive show circuit, has just received quite a shock! His award-winning cat, Emeline, has given birth to some surprising kittens. Of her five kittens, four have black fur, and one has an unexpected coat of fur that is a patchwork of black and orange, known as a tortoiseshell pat- tern. Mister Poppleton was breeding Emeline with an award-winning male cat, named Barnaby, but he is now worried that Emeline may have been having secret sexual relations with a neighbor- hood stray cat, named Hugo. Mister Poppleton consults with his veterinarian, Dr. Doolittle, for some expert advice.
Dr. Doolittle explains: In cats, there are several genes that determine fur color. One of those genes is found on the X chromosome and codes for whether a cat has orange fur or black fur. Be- cause it is a sex-linked gene, it is expressed a bit differently in males than in females. In males: If a male cat has the orange allele on his X chromosome, he will have orange fur. . If a male cat has the black allele on his X chromosome, he will have black fur. In females: • If a female cat has the orange allele on both of her X chromosomes, she will have orange fur. . If a female cat has the black allele on both of her X chromosomes, she will have black fur. • If a female cat has the orange allele on one of her X chromosomes and the black allele on the other X chromosome, she will have a tor- toiseshell coat. With this information in mind, Mister Poppleton takes a closer look at Emeline and the possible fathers (Barnaby and Hugo) of her kittens. Eme- line is a female cat with all-black fur. Barnaby is a male cat with all-black fur. Hugo is a male cat with all-orange fur.