Genotype vs Phenotype

A genotype is an individual’s collection of genes. The term also can refer to the two alleles inherited for a particular gene. The genotype is expressed when the information encoded in the genes’ DNA is used to make protein and RNA molecules. The expression of the genotype contributes to the individual’s observable traits, called the phenotype.

Humans contain two copies of each gene, one from the father and one from the mother, which sometimes are referred to as the alleles of a gene. If a mutation occurs in just one copy of the gene then that individual is considered heterozygous. On the other hand, if both copies of a gene are mutated then that individual is homozygous genotype.

Most hereditary disorders are harmful if both copies and alleles of a genotype are affected, which means protein products from both genes may fail to operate properly. In such cases, immediate medical attention is needed so the function of a defected protein can be restored through medication. In heterozygous genotypes, one copy of the gene is healthy and can produce fine proteins thus these individuals are usually not affected and are considered just carriers. However, in a few hereditary disorders, heterozygous individuals may suffer from a lesser version of the disease.

This genetic constitution of individual influences – but is not solely responsible for – many of its traits. The phenotype is the visible or expressed trait, such as hair color. The phenotype depends upon the genotype but can also be influenced by environmental factors.


Genotype is the genes responsible for:

  • eye color

  • hair color

  • height

  • how your voice sounds

  • certain diseases

  • certain behaviors

  • the size of a bird’s beak

  • the length of a fox’s tail

  • the color of stripes on a cat

  • the spots on a dog’s back

  • a person’s shoe size


genotype vs phenotype