Kaplan Nursing Entrance Exam Practice 2025 – Comprehensive Prep

The term phenotype refers specifically to the physical expression of inherited traits in an organism. This includes observable characteristics such as height, eye color, and other physical attributes that result from the interaction between an organism's genetic makeup (genotype) and environmental factors. The phenotype is essentially the manifestation of the genetic information and can vary widely among individuals, even when they share similar genotypes. This distinction is crucial in genetics because while the genotype provides the underlying instructions, it is the phenotype that is visible and measurable.

Other options address different aspects of genetic theory: the genetic makeup refers to the underlying alleles present, dominant traits describe how certain traits can be expressed over others within a population, and genetic variation involves the diversity in alleles and genotypes among individuals. Each of these concepts is important in genetics, but they do not define what phenotype means.