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1. Genes often interact with one another. The term epistasis isapplied to cases in which one gene alters the expression of anothergene that is independently inherited. In Labrador retriever dogsone gene locus is involved with production of melanin pigment: B(black) and b (brown) are its two alleles. Another gene locusdetermines whether the melanin produced is actually deposited inindividual hairs as they grow (E) or not deposited (e). Any dogwith at least one dominant allele B and one dominant allele E willbe a black Labrador. A dog with the homozygous recessive bb and atleast one dominant E will be a lighter, chocolate Labrador. If adog has the homozygous ee genotype it will be a yellow Labrador,regardless of the alleles at the pigment locus.

   1. Give possible genotypes for a dog with the black Labradorphenotype?

      With respect to locus B

      With respect to locus E

   2. Give possible genotypes for a dog with the chocolate Labradorphenotype?

      With respect to locus B

      With respect to locus E

   3. Give possible genotypes for a dog with the yellow Labradorphenotype?

      With respect to locus B

      With respect to locus E

2. A yellow Labrador with the genotype bbee mates with a blackLabrador that is homozygous for both alleles. What are the ratiosof genotypes and phenotypes expected in the F1 and F2generations?

P.S More in Need for help with Question 2.