Genotypes are the genetic makeups of organisms and are typically referred to with respect to the specific traits they describe. Genotypes exist in the form of genetic data such as DNA or RNA. While it is typically used to describe the genetic basis for a specific trait, the term genotype can also be used to represent the summation of a creature's genetic code. The term even applies to genetic information that is not expressed in some visible trait, as some genetic code is not actually observably expressed but is still a part of an organism's overall genetic information.
Genotypes are often studied in the fields of biology, biochemistry, and medicine because of their links to heredity. Parents pass many traits down to their offspring through their genetic data. Heredity can be explained through an understanding of the genetic code and the way that it is passed from parents to offspring. Traits are passed down through genes which are made up of two parts, or alleles. If the gene has a dominant allele, it will be expressed; if it has two recessive alleles, it will not be expressed.
Different combinations of dominant and recessive alleles can lead to different results concerning the expression of a gene. Parents can pass down various combinations of alleles to their offspring, leading to certain traits being expressed or suppressed. The combination of alleles and genes present in organisms makes up their genotypes. Phenotypes, on the other hand, are the actual observable forms of the traits. Two alleles on a gene may determine that an individual has blue eyes; the alleles compose the genotype and the blue color is the phenotype.
The use of genotypes to understand heredity is particularly interesting because of the potential to predict and correct illnesses and disorders in individuals based on the genetic makeup of their parents. Many different disorders are clearly apparent based on an individual's genetic makeup. One disorder that is commonly predicted from a genetic basis is hemophilia, a disorder that inhibits the blood's ability to clot properly.
Many students of biology initially confuse genotypes and phenotypes, but the distinction is of the utmost importance. The genotype of an organism or specific trait refers specifically to the genetic information that describes a visible trait. A visible trait, such as eye color or hair color, can not be described as a genotype. Phenotype, on the other hand, specifically refers to those traits that can be described from observation. Genotypes are the factors that cause specific phenotypes to exist.