Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Dog puppies inherit many visible traits from their parents - such as coat color, fur length, ear shape, and body size. These traits are controlled by genes passed from parents to offspring. However, because each puppy receives a unique mix of genes from both parents, variation exists even among littermates.
One of the best examples of inherited and variable traits is coat color.
In Labrador retrievers, for example, coat color is determined by two interacting genes:
One gene controls pigment color (black or brown).
Another gene controls whether pigment is expressed at all (yellow if “off”).
This means that two black Labradors can produce yellow or chocolate puppies if they both carry recessive genes - showing that appearance alone doesn’t reveal all genetic information.
Researchers from the American Kennel Club (AKC) Genetics Program analyzed color inheritance in multiple Labrador litters:
Parent pair 1 (Black × Black): 70% black, 25% yellow, 5% chocolate puppies
Parent pair 2 (Black × Yellow): 50% black, 50% yellow puppies
Parent pair 3 (Chocolate × Yellow): 40% chocolate, 60% yellow puppies
Even though the parents share many genes, genetic combinations produce observable variation. The same applies to fur length - puppies of short-haired parents usually have short coats, but if one carries a recessive long-hair gene, variation appears.
This variation among offspring provides evidence that traits are inherited from parents but are not identical among all individuals in a species.
Parent Pair | Black Puppies (%) | Yellow Puppies (%) | Chocolate Puppies (%) |
|---|---|---|---|
Black × Black | 70 | 25 | 5 |
Black × Yellow | 50 | 50 | 0 |
Chocolate × Yellow | 0 | 60 | 40 |
Parent Combination | Short-Haired Puppies (%) | Long-Haired Puppies (%) |
|---|---|---|
Short × Short | 90 | 10 |
Short × Long | 60 | 40 |
Long × Long | 10 | 90 |
Make a claim, provide the evidence, and explain your reasoning for the statement:
“Traits such as coat color and fur length are inherited from parent dogs, but variation exists among offspring.”
In your response, clearly label the parts as:
Claim:
Evidence:
Reasoning:
Refer to Tables 1 and 2 in the Dog Coat Color and Length resource.
What patterns can you identify about how parent combinations influence the traits of their puppies?
Which statement best describes what the data in Table 1 show about coat color inheritance?
Why might two short-haired dogs produce a long-haired puppy?
Explain how the inheritance of coat traits connects to the dog’s life cycle from birth to adulthood.