A genotype is a group of organisms sharing a genetic 'constitution', or in some cases may refer to a specific genetic characteristic as the type definition. A genotype may contain groups of sub-types, or particular characteristics which are shared by some members of the major genotype but not others. Genotypes may refer to specific alleles in particular locations, hence the need to express the genotype with a classifier.
Examples of Genotype:
|Species members share a natural common genotype.|
Sub-species share some elements of a genotype, but may also have specific elements in common with other sub-species.
Some bacteria may have common alleles within a bandwidth of species. (This helps identify many species types.)
Here the relation between genotype and phenotype is illustrated, using a punnett square, for the character of petal colour in pea. The letters B and b represent genes for colour and the pictures show the resultant flowers.