Describes the observable traits resulting from the underlying genetic makeup of the individual.

Phenotype and genotype are companion terms that describe an individual's genetic makeup. The genotype is the complete description of an individual's genetic traits. The phenotype describes the outcome of the genotype, but may not always reveal the complete genotype. For example, the gene for blue eyes is recessive—both mother and father must contribute the gene for blue eyes to the child's genotype for the child to exhibit blue eyes in his or her phenotype. The child may have a recessive gene for blue eyes in his genotype, while having brown eyes in his phenotype. The differences in genotype (the underlying genetic makeup) and phenotype (the expression of the genetic makeup) are important in diagnosing and intervening in genetically transmitted diseases or syndromes caused by recessive genes.

See Also

Genotype