Not all the living organisms in the world look and act the same. This variety in life is largely attributed to the genetic makeup of the organisms. It has always been felt that one’s genes play a great role in the diversity that we see around the world and the individuality of an organism. Genotype and Phenotype are two terms which can be used to understand differences in organisms.

Both genotype and phenotype are terms which are used to define and differentiate between the genetic makeup of an organism and how the genetic makeup is reflected in the organism. A lot of differences can be listed between the two terms.

Differences between Genotype and Phenotype:

• Genotype, a term coined by the Danish geneticist Wilhelm Johannsen can be defined as the genetic makeup of a cell of an organism. A cell will contain information about each character or trait of an individual in its two alleles. One of the alleles is obtained from the mother and one from the father. The physical expression of the genetic makeup in the organism is called Phenotype. In other words the genetic makeup is observed in the organism as behavior or physical characteristics.
• Examples of Genotype are the DNA of an organism and the organism’s inherent capacity to be susceptible to diseases. The presence or absence of a disease or certain symptoms of a disease are also determined by phenotypes. Physical characteristics such as color of the hair, eyes, weight, height and others are examples of phenotypic expressions.
• Genotype is depended upon factors such as hereditary information that has been passed to the offspring through the parental genes. Genotype and the environmental factors determine the phenotype. Phenotypes are modified by the environmental factors while the genotype of an individual is never modified. For example, when an infant starts teething is determined by genotype. However, environmental conditions like diet and water can make the teeth fall sooner or later.
• The status and traits of a new born child is completely based on the genotype. However, the phenotypes which are influenced by the environment determine the child’s development from infancy to an adult.
• The genotype of an individual is partly passed on to the next generation as one of the alleles of a cell is transferred to the offspring. Phenotype is never passed on to the next generation.
• The genotype is a comprehensive catalogue of all the hereditary information of an individual and is passed on by the parents during conception. A genotype includes the complete set of alleles that the individual has got from the parents. Genotype also determines the various combinations of traits that are possible with the alleles available. However, only a small set of genes are expressed as phenotypes. Consequently phenotypes have only the expressed genes. For example, an individual can have both brown eye allele and a black eye allele in the cells. This is the genotype. However, if the person has only brown eyes then the phenotype will include only the brown eye allele which has been physically expressed in the individual.
• Genotyping or understanding the type of genes contained in the alleles of the cells in an individual’s body can be done through a biological assay using PCR techniques. However, phenotypes can be gauged easily by observing the external characters that are seen on the body.

Studies have proven that many genes when interacting with numerous environmental factors produce different phenotypes. The genotype and phenotype relationship provides an answer to the diversity that makes the world an interesting place to live in.