Question

Breeding Labrador Retrievers, yellow labs always have pink noses, and black labs always have black noses. What is a possible explanation for this occurrence?

A) Genetic Mutation
B) Environmental Factors
C) Dominant and Recessive Genes
D) Random Chance

Answer 1

The correlation between nose color and fur color in Labrador Retrievers is probably due to Dominant and Recessive Genes, where yellow labs have pink noses due to recessive alleles (ee_), and black labs have black noses due to the combination of dominant alleles (B_E_).

Step-by-step explanation:

The phenomenon where yellow Labrador Retrievers always have pink noses, and black labs always have black noses is likely explained by C) Dominant and Recessive Genes. In the genetics of coat and nose color among Labradors, the presence of certain alleles dictates the resulting nose and fur color. Yellow labs have the genotype ee_, which indicates the expression of recessive alleles leading to the absence of black pigment and resulting in a pink nose. Black labs have a dominant allele B in combination with E (B_E_), which leads to the production of black pigment in the fur and the nose.

An example of the relationship between coat color and nose color can be seen in the genetic explanation provided for Labrador Retrievers, where a gene affecting pigment (E) presents the epistatic property, overshadowing the expression of another gene (B) for black coloration in certain scenarios, as explained by the presence of ee_ vs. B_E_ genotypes.