Final answer:
A person's observable characteristics are his or her phenotype, which is determined by the interaction between genotype and the environment.
Step-by-step explanation:
A person's observable characteristics are called phenotype. These characteristics are the result of the interaction between an individual's genotype and the environment. The genotype refers to an individual's genetic makeup, which is represented by the combination of alleles for each trait.
Learn more about Observable characteristics and their genetic basis