Question

In minks, coat color is controlled by a single gene. The allele for a brown (B) coat is dominant to the allele for silver blue (b) coats.

B = brown coats
b = silver blue coats
A homozygous brown mink was crossed with a silver blue mink. There were 9 offspring in the first generation. What color were they? (brown or silver blue)

Answer 1

The offspring in the first generation were all brown.

Step-by-step explanation:

In Mendelian genetics, the dominant allele (B) masks the expression of the recessive allele (b). When a homozygous brown mink (BB) is crossed with a silver blue mink (bb), the resulting offspring in the first generation (F1) will all inherit one dominant allele from the brown mink parent and one recessive allele from the silver blue mink parent.

Therefore, they will be heterozygous (Bb) and exhibit the dominant brown coat color. The brown coat color is expressed phenotypically, while the silver blue allele is present in the genotype.

Understanding Mendelian inheritance patterns is crucial in predicting the outcomes of genetic crosses. The Punnett square, a visual representation of possible genetic combinations, can be used to determine the expected genotypes and phenotypes of offspring. In this case, the cross of BB (homozygous brown) with bb (silver blue) results in all Bb (heterozygous brown) offspring in the F1 generation, leading to brown coat color expression.

This example highlights the straightforward nature of single gene inheritance, where the dominance of one allele over another determines the phenotype. The observation that all offspring in the first generation are brown provides insights into the genetic makeup of the parental minks and the principles of dominant-recessive inheritance.