1) Genetics Project Outline and Info PDF

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Genetics info....

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Inheritance of Coat Color in Labrador Retrievers Introduction Labrador Retrievers come in three colors: black, yellow and chocolate (brown). In recent years, the chocolate color has become increasingly popular. You have been hired as a genetic consultant to two kennels who are currently breeding black labs. They want to know if it is possible for them to get chocolate puppies from the dogs they have. You will need to consider each animal’s genetics in order to select the pair that is most likely to produce the chocolate coat color. In your recommendation, you will need to provide the data and analysis necessary to justify accepted and rejected breeding pairs. Since the breeders have no genetic training, your presentation should include a basic explanation of inheritance. It should also be presented in a professional format such as a PowerPoint, video, brochure, or flip chart. Two gene pairs determine coat color in Labs. One pair is the color gene and the two possible alleles are B (black) and b (chocolate), so black is dominant over chocolate. The other gene pair is epistatic. An epistatic gene is one that affects the expression of another gene. For example, in labs, black color is dominant over the chocolate color. However, if a dog has two recessive alleles for the epistatic gene (ee), the dog will be yellow regardless of the color genes it possesses. Also, the gene combination eebb (homozygous recessive for both the epistatic gene and the color gene) should be avoided because it produces a dog with a yellow coat and chocolate pigmentation of the nose, lips and eye rims. A dog with this gene combination is called a Dudley and does not meet AKC standards, which require yellow Labs to have black nose, lips and eye rims.

Remember: The goal is to produce as many chocolate puppies as possible while avoiding a Dudley.

Part I: 1. Project Task Worksheet 1 will help you become familiar with interpreting allele combinations. 2. A Step Further: Do some research about epistasis and Labrador Retriever coat color inheritance.

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Meet the Dogs! Today, you got to visit the kennels and meet the dogs. The owners also submitted genetic records for the parents (sire and dam) of each dog. Kennel 1:Magnolia Farms Three black females.

Kennel 2: North Shore Kennels Three black males.

Roxy Sire: EEBb Dam: Eebb

Bear Sire: EEBB Dam: eeBb

Daisy Sire: EeBb Dam: EEBb

Kona Sire: EeBb Dam: Eebb

Stella Sire: EEbb Dam:eeBB

Dexter Sire: EeBb Dam: Eebb

Part II: 

Draw Punnett Squares for each dog’s parents to help you determine the possible genotypes of the 6 dogs.

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Just In - More Information from the Kennels! The kennels just emailed some more information about previous litters: 1- Bear was previously bred with a chocolate female and produced a litter of 9 black puppies. 2- Kona previously sired 2 litters with a yellow female producing 8 black puppies in the first litter and 6 black puppies in the second litter. 3- Dexter was bred with a black female and produced 2 yellow, 3 chocolate, and 3 black puppies. 4- All three females have had yellow puppies in previous litters.

Part III: 

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Project Task Worksheet 2 will provide practice in interpreting Punnett Squares and determining possible offspring. Use the information from previous litters to help narrow down the genotypes of each dog. Now, it’s time to make your decision about which dogs to breed and organize your presentation for the kennels.

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