What determines the appearance of offspring when present?

The appearance of offspring, also known as the phenotypic expression, is primarily influenced by dominant alleles when they are present. A dominant allele can mask the effects of a recessive allele, leading to a phenotype that reflects the traits associated with the dominant allele. For instance, if a dominant allele for flower color is present in a plant, the plant will express that flower color, regardless of whether it also carries a recessive allele for a different color.

In genetics, the dominance relationship between alleles is crucial for determining the phenotypes of organisms. When a dominant allele is paired with a recessive allele in an offspring's genotype, the dominant allele's traits are the ones that are visibly expressed. This is why recognizing the role of a dominant allele is essential when predicting the outward characteristics of offspring.

Other options, such as the phenotype and genotype, refer to different aspects of genetic expression. The phenotype is the actual observable characteristics, while the genotype refers to the genetic makeup that can include both dominant and recessive alleles. Recessive alleles require two copies to express their traits, making them less influential when a dominant allele is present. Therefore, the presence of a dominant allele is what directly influences and determines the visible traits of the