Question

in labrador retriever dogs, the black coat color allele (b) is dominant over the chocolate coat color allele (b). however, some litters produce dogs that have a yellow coat color. scientists have determined this is because of a second gene that can influence coat color. if this eumelanin gene is recessive for both alleles (e), the dogs coat will be yellow regardless of the alleles for the other coat color gene.
a dog breeder sets up a cross between a dog that is homozygous dominant for coat color (bb) and heterozygous for eumelanin (ee) with a dog that is homozygous recessive for coat color (bb) and heterozygous for eumelanin (ee).
place the dogs in the punnett square to show the coat color phenotypes that would result from this cross.

• you may use each dog more than once.
• you should fill all the blank boxes in the punnett square.

what would you type in the c box?
bbee
bbee
bbee
rbee

Explanation:

Step1: Determine the gametes of each parent

• The first parent is \( BB Ee \). Its gametes are \( BE \) and \( Be \).
• The second parent is \( bb Ee \). Its gametes are \( bE \) and \( be \).

Step2: Analyze the cross for box C

• Box C is the result of \( BE \) (from the first parent) and \( be \) (from the second parent).
• When we combine these gametes, we use the rules of Mendelian genetics for allele combination. For the coat - color gene (\( B/b \)): \( B\times b = Bb \). For the eumelanin gene (\( E/e \)): \( E\times e=Ee \). So the genotype is \( BbEe \).

Answer:

\( BbEe \)