Question

Rooster feathering in chickens is inherited with the autosomal recessive allele r. Hen feathering is inherited with the autosomal dominant allele R. The trait is sex-limited. Only males will show rooster feathering. A male chicken with the genotype Rr will show ______ feathering?

1) Rooster
2) Hen
3) Cannot be determined

Answer 1

A male chicken with the genotype Rr shows hen feathering because the allele for hen feathering (R) is autosomal dominant and overrides the recessive rooster feathering allele (r). Option 2 is correct answer.

Step-by-step explanation:

A male chicken with the genotype Rr will show hen feathering. The allele for hen feathering (R) is autosomal dominant, while the allele for rooster feathering (r) is autosomal recessive and the trait is sex-limited, meaning only males can express the rooster feathering phenotype.

However, since the R allele is dominant, it dictates the phenotype; thus, a male chicken with an Rr genotype would exhibit hen feathering because it has at least one dominant allele (R), which is sufficient for the trait to be expressed phenotypically.

In terms of genetics and dominance relationships, whether an allele is dominant or recessive determines how it will be expressed in the phenotype. In this case, the dominant allele (R) for hen feathering overshadows the recessive allele (r), leading to the expression of hen feathering in the presence of a single R allele. This would be the case even though the rooster feathering trait is sex-limited to males.

The final answer which option is correct: 2) Hen feathering.