Difference between Genotype and Phenotype

The terms genotype and phenotype may sound similar but they have different meanings. Let us see how genotype differs from phenotype!

Genotype:

Genotype refers to the genetic makeup or genetic characteristics of an organism. It is a set of genes in the DNA which is responsible for the different traits of a living organism. In other words, genotype tells us what genes a living organism has for a particular trait. For example, people with blue eyes must have genes for blue eye colour in their genotype.

In all living organisms including humans, the genes which are transmitted from parents to their offspring make up the genotype of the offspring. Just like fingerprints, no two persons have the same genotype, except the identical twins. The genotype, the environmental influence on the genotype and random variation determine the actual appearance and behavior of an individual.

Phenotype:

Phenotype refers to the visible physical characteristic of a living organism such as height, skin colour, eye colour, behavior and development of an individual. The phenotype of an organism is determined by its genotype (set of genes), the environmental influences on these genes and random variation. In other words, if the genotype is a code, the phenotype is the manifestation of the code.

Due to the influence of environment, two organisms with the same genotype like identical twins may express different phenotypes as each organism encounters a different environment as it grows. Phenotype not only includes the observable characteristics such as morphology but also includes characteristics that can be measured in the laboratory like levels of blood cells, hormones and structures such as RNA and proteins which are produced as per the genetic makeup.

Based on the above information, some of the key differences between Genotype and Phenotype are as follows:

GenotypePhenotype
It is the genetic makeup of an organism.It is the visible physical characteristic or morphology of an organism like eye colour, skin colour, height etc.
It comprises genes which are transmitted from parents to offspring.It is determined by genotype, environment influence on genotype and random variation.
It is partially inherited by offspring as one of the two alleles from one parent is passed on during reproduction.It cannot be inherited.
Examples include the different genes or sets of genes in a DNA which are responsible for different traits like blue eyes, dark hair, fair complexion etc.Examples include eye colour, hair color, skin colour, behavior etc.
It remains the same throughout the life of an individual.It changes with time, e.g. infant, adult, and old.
It cannot be studied through direct observation, it can be determined by genotyping or by studying ancestors, mating and offspring.It can be determined through direct observation.
It is not influenced by phenotype.It is the visible expression of the genotype. Genotype establishes the limits within which a phenotype can be expressed.
In a given environment, individuals with similar genotype generally have the same phenotype.Individuals with similar phenotype may have different genotype.
It is not influenced by the environment.The environment can influence the phenotype.




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