What influences the appearance of a trait in a genotype?

The appearance of a trait in a genotype is influenced by a combination of both alleles. In genetics, traits are expressed as a result of the interaction between alleles inherited from an individual’s parents. Each individual inherits two alleles for each gene: one from each parent.

If both alleles are dominant, the dominant trait will manifest in the phenotype. If one allele is dominant and the other is recessive, the dominant trait will still be expressed. However, if an individual has two recessive alleles, the recessive trait will be expressed. Therefore, the phenotype—the observable characteristics of an organism—is determined by the combination of alleles present in the genotype. This interplay between alleles is fundamental to understanding how traits are passed down and expressed in offspring.

While environmental factors can also influence the expression of traits, they do so by interacting with the genetic makeup rather than being a sole influence on their appearance. Thus, the correct understanding lies in recognizing that both alleles are crucial in determining how a trait is expressed.