What is a genotype?

A genotype refers specifically to the genetic constitution of an individual, which encompasses the alleles that an organism carries for a particular trait or set of traits. This genetic makeup determines an organism's potential characteristics, although the expression of these traits can be influenced by environmental factors.

Understanding the genotype is crucial in genetics because it allows scientists to predict inheritance patterns, study genetic variation within populations, and explore how certain traits are passed from one generation to the next. While the physical expression of traits, known as the phenotype, is important, it is the genotype that provides the underlying genetic foundation for those traits.

The other concepts mentioned, such as the observable characteristics of an organism and the study of heredity and variation, are related but do not accurately define what a genotype is. The relationship between genotype and phenotype is key in genetics, highlighting how an individual's genetic information can lead to specific traits and how these traits may manifest in observable ways.