Genotype and phenotype are very similar-sounding words that are related, but actually mean different things. The genotype is the set of genes in our DNA which is responsible for a particular trait. The phenotype is the physical expression, or characteristics, of that trait. For example, two organisms that have even the minutest difference in their genes are said to have different genotypes. These two mice may have different genotypes and both can still be white if they share the particular phenotype for white fur.
Comparisons of Genotype & Phenotype
Genotype is what makes the trait – the information within a gene, or the genetic makeup of a specific organism. Genotype is determined by the makeup of something called “alleles,” a word that refers to the form of a gene that produces different effects.
Genotype is the information contained within two alleles. Genotype is the genetic makeup of an organism and it results in some of the physical characteristics of that organism.
Genotypes can only be determined by biological tests, not observations. Genotype is an inherited trait and hereditary information passed by the parents determines genotype. The entire genetic information about an organism is contained in a genotype – even those characteristics which are not expressed visually.
Examples of genotype are the genes responsible for:
- eye color
- hair color
- 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
Phenotype is what you see – the visible or observable expression of the results of genes, combined with the environmental influence on an organism’s appearance or behavior. For example:
- It is the expression of gene information which is observable with the senses (like the sound of a bird’s chirping or the color of a cat’s hair)
Phenotype can be determined by mere, simple observation. Examples of phenotypes are the actual visible characteristcs including:
- Eye color
- Hair color
- Sound of your voice
- Certain types of disease
- Certain behaviors
- Size of a bird’s beak
- Length of a fox’s tail
- Color of the stripes on a cat
- Size and shape of the spots on a dog’s back
- An individual’s shoe size
With these examples, it is easy to see the difference between genotype and phenotype and to understand how these two concepts relate to each other. The next time you look at different traits that you have, or that you see in other people or animals, you can better understand genotype and phenotype.