What is defined as the gene makeup of an organism?

The gene makeup of an organism is referred to as the genotype. The genotype encompasses all the genetic information that an organism carries, including variations in genes that may not necessarily be expressed. It provides the underlying blueprint for the organism's potential traits and characteristics, determining how these traits may manifest physically, which is known as the phenotype.

In contrast, phenotype pertains to the observable traits and characteristics like physical appearance, behavior, and physiological properties, but it does not capture the entire genetic makeup. Alleles are specific versions of a gene that may exist within an organism's genotype, and traits are the resulting expressions of the genotype in a particular environment. Understanding the distinction between these terms is crucial in the study of genetics and heredity, as genotype is fundamentally what determines potential and hereditary characteristics.