The expression of life begins from genes. These are the ones that determine the physical features of a person, the behavior of each individual and their biochemistry. Some are the genotype and, others, the phenotype. While they are closely related, they are not the same. In this ecology article, we will explain the main Differences between genotype and phenotypeas well as its definitions and practical examples so you can understand its importance.
Definition of genotype and phenotype
As we have mentioned, both genotype and phenotype are related. But, still, it is not about the same concept. Next, we will explain more in detail what a genotype and a phenotype is.
Genotype
The genotype in biology is the hereditary contentthat is to say the genetic composition of an organism. It can be represented in Mendelian factors, such as alleles, genes or in the representation that is being used for genetic determinants. It can also refer to the set of genes characteristic of a species.
Phenotype
The phenotype in biology are elements expressed by genes. The genotype contains genetic information that must be manifested in concrete elements and, to these elements, it is what we know as a phenotype. That is, the Genotype dictates to the phenotype. The word phenotype comes from Greek Phaineinwhich means being visible. It is understood then that the phenotype is the visibility of the genes.
The elements to be expressed phenotypically can be physical featuresas the concept was initially created by Mendel during his Guisante experiment, as it can also be biochemical, developmental or even behavior. We cannot say that the phenotype are visible characteristics, since genetic expression can occur to non -visible levels For man, as is all the complex machinery that occurs at the cellular level.
Here are seven differences between the phenotype and the genotype.
The genotype includes genes and the phenotype to the expression of the components
The genotype is stored as DNAin sequences created by nucleic bases. These are reduced to four:
- Adenine
- Timina
- Cytosine
- Guanina
The combination of these four bases, accommodated in complementary pairs, creates the genes. But the phenotype is expressed in a Huge number of components. They can range from enzymes, hair color, reproductive behavior, size, life time, circadian cycle, among many others.
The genotype is unique, the phenotype can be the same
There may be equal phenotypes for different genotypes. The genotype includes the genetic information that an organism represents, both of recessive and dominant genes:
- The recessive genes They need to be homozygous to be expressed.
- The dominant genes They can be heterozygous.
When they have a dominant heterozygous gene express the phenotype of the dominant gene and not that of the recessive. Later you find an example about this. Phenotypes show Only heterozygous genes dominant or recessive.
The genotype is transmitted, the phenotype is expressed
Organisms receive from their parents the genetic information, with sequences from both parties selected by genetic recombination. On the other hand, the phenotype and its expression is the task of the child organism.
If you want to know more, we recommend that you take a look at this other article on genetic recombination: what is and examples.
The genotype is not visible, the phenotype yes
The genotype contains fundamental information packaged DNA -shaped. This information must be expressed so that it can act within time and space. The phenotype is the expression of the genotype, which although it is not visible as such, attending to what we propose as phenotypic characters previously, Yes it is tangible and decoded.
The genotype cannot be modified by the environment, the phenotype yes
While the genotype has certain characteristics that will be expressed, for example in physical features the complexion or skin color, the environment to which the phenotype can be modifiedsuch as if an individual is in a sedentary state, his Physical structure will change.
It is important to mention that there are those who claim that only the phenotype can be modified by the environment, but recently it has been discovered that the environment does have an effect on genes. This science is known as epigenetics and demonstrates that both the habits we have, as well as the food (the use of tobacco), among others, can Activate or deactivate genes In organisms.
An example of this is alcoholics, who have a vitamin deficiency and, therefore, there are methylations in the DNA where it is not due, which activates multiple diseases, including cancer.
Finally, it should be re -recidized that the genotype is not modifiedthere is only influence on how the genes that already exist in the genotype are expressed.
The phenotype depends on the genotype, but not vice versa
The phenotype is expressed by the genotype, there can be no characteristics that have not been previously determined by the genotype. He phenotype cannot dictate How the genes will act.
The phenotype always expresses something tangible and concrete, the genotype does not
The genotype can present instructions to express the concrete genesbut there are also sequences that have regulatory instructions, that is, they activate or deactivate genes. The phenotype is expressed as Tangible modebut the genotype not only contains information for characters, but also regulatory.
Examples of genotype and phenotype
Next, we will present two examples of genotype and phenotype that serve to see the differences they entail.
Mendel’s peas experiment
The most useful example to explain to the genotype and phenotype is the experiment of Mendel’s peas, the initiator of the inheritance studies. Mendel noticed that peas had certain physical characteristics and that something should dictate that they were like that. The phenotype of the peas was the physical characteristic: smooth or rough. The smooth had genotype A, so if they were crossed pollen with ovules A, they would give peas AA, that is, smooth. The rough peas have genotype a. Now, if an ovule with genotype A and smooth phenotype is taken, and a rough phenotype genotype pollen, it would have an AA genotype.
The written genotype with capital letters always corresponds to the dominant gene and the recessive is written in lowercase. The result of the progeny will be of smooth phenotype, because this is the dominant gene.
Hair color on the cross -live cattle
Another example of phenotype and genotype can be applied to hair color on the crossing of Shorthorn cattle. RR genotype bulls have red hair and RR phenotype cows have white hair. When crossing them, they will give as a parent, or cows, of the RR genotype expressed as Ruano phenotypethat is, they have brown hair with white hairs in uniform way. When crossing this generation again, red phenotypes with RR genotype, Ruano phenotype with RR or white genotype with RR genotype can be generated. This crosslinking helps to explain that of a same initial genotype may be different phenotypes.
Not only can two alleles exist, but there may be multiple alleles for a gene. This is the case of human blood groups, in which there are phenotypes A with Genotype AA or AA, B with genotype ABTOB or aBa, AB phenotype with AA genotypeBand phenotype or with AA genotype. The knowledge of the genotype helps to be done Blood transfusions with the correct phenotypes Because of not doing so, adverse reactions of incompatibility could occur.
If you want to complete your knowledge on the subject, do not hesitate to visit this other ecology article about cell biology: what is and its importance.
If you want to read more articles similar to Difference between genotype and phenotypewe recommend that you enter our biology category.
- Gómez-Pompa, A., Barrera, A., Gutiérrez-Vázquez, J., & Halffter, G. (1980). Biology: unity, diversity and continuity of living beings. Mexico City: National Council for the Teaching of Biology.
- Medawar, P., & Medawar, J. (1988). From Aristotle to Zoos: a philosophical dictionary of biology. Federal District: Economic Culture Fund.
