what is genotype in science

In science, genotype refers to the genetic makeup of an individual cell or organism that determines or contributes to its phenotype. It can be described as the combination of alleles that an individual possesses for a specific gene. Genotypes can be represented by symbols, such as BB, Bb, bb, or by the actual DNA sequence at a specific location, such as CC, CT, TT. The term can be used to refer to the alleles, or variant forms of a gene, that are carried by an organism. Humans are diploid organisms, which means that they have two alleles at each genetic position, or locus, with one allele inherited from each parent. Each pair of alleles represents the genotype of a specific gene. For example, in sweet pea plants, the gene for flower color has two alleles. One allele codes for purple flowers and is represented by the uppercase letter F, whereas the second codes for white flowers and is represented by the lowercase letter f. A varied population of sweet pea plants could therefore feature three possible genotypes at this locus: FF, Ff, or ff. The phenotype of an organism describes the physical or physiological features of an organism and is the consequence of the expression of the genotypes. However, the genotype is not the only factor that will determine an individual’s phenotype. Various environmental factors also have a role, and these influence the expression of the genes to determine the distinctive phenotype of an organism.