The actual gene make-up of an organism is its genotype. Genotype refers to the specific combination of genes that an individual organism carries. It is the genetic information that is inherited from both parents and determines the organism's traits and characteristics. The genotype of an individual is distinct from its phenotype, which is the observable characteristics or traits that are expressed as a result of the interaction of the genotype with the environment. For instance, the genotype of an individual determines their eye colour, but the actual eye colour expressed may be influenced by environmental factors such as exposure to sunlight.