Kaplan Nursing Entrance Exam Practice 2026 – Comprehensive Prep

The phenotype of an individual is primarily determined by the genotype of the organism. The genotype refers to the specific genetic makeup of an organism, which includes all of its alleles and genes inherited from its parents. This genetic information provides the blueprint for the development of physical traits and characteristics, such as eye color, hair type, and susceptibility to certain diseases.

While the environment can influence the expression of certain traits, it does not fundamentally determine the phenotype. Factors such as nutrition, climate, and lifestyle can interact with the genotype and affect how certain traits are manifested. However, the underlying genetic code serves as the primary guide for what traits an organism can express.

The number of cells in the organism and the size of the organism may relate to overall health and development, but they do not influence the traits or characteristics that define an individual’s phenotype. These aspects are more a result of the phenotype rather than determinants of it. Thus, understanding the relationship between genotype and phenotype is crucial for comprehending how genetic factors underpin biological diversity.