In this article, we will consider one of the most important elements of the body that forms the structure of hereditary information at the molecular level - the genotype. This set of fragments, formed by nucleotides, five-carbon sugar and phosphoric acid residues and creating amino acid sequences, is responsible for the manifestation of all the signs of a living organism.
Introduction
A genotype is a collection of genes of a specific individual. This concept differs from the gene pool in that it characterizes only a specific individual. Speaking in a narrower sense, a genotype is a combination of allelic genes or their loci in a particular living being and viruses. The genotype through interaction with an external set of factors creates a phenotype. This is despite the fact that 2 individuals with different genetic information will have the same phenotypic trait, and an individual with the same genotype will be able to show different traits when conditions change.
The term genotype, as well as gene and phenotype, was introduced into the circulation of scientific speech by the geneticist V. L. Johansen (1909) in a book on the elements of the exact doctrine of heredity (Elemente der Exakten Erblichkeits Lehre).
Related information
What is usually meant by genotype? This is a collection of genes responsible for storing hereditary information about us. They are the basis of hereditary information.
A phenotype is all the signs and properties of an organism that are expressed in the course of individual growth and development in a certain climate, pollution or purity conditions, etc., and are the result of mutual work with information recorded in the genotype.
Modifications
A genotype is a collection of traits expressed in genes. It is closely related to the course of variability - a phenomenon observed during the interaction of a changing environment with hereditary information. On its basis, a genetic difference appeared in the data forms. The following varieties of variability are distinguished: phenotypic (modification) and mutational (genetic) type.
The processes of modification variability do not affect the genotype, but are based on the response of the same hereditary gene code in response to changes in conditions. Using the optimal factors of the internal and external environment, it is possible to determine the maximum fate of the capabilities of the genotype at a particular point in time.
The manifestation of modification variability occurs only in a quantitative or qualitative deviation from the original form, and it is not transmitted as hereditary information, but is only an adaptive tool. An example is skin pigmentation in people under ultraviolet rays or an increase in muscle development in response to regular exercise. The human genotype is a means of forming our phenotype, and it is not inherited, which is primarily due to sexual reproduction.
Reaction rate
There is the concept of a reaction rate, which determines the degree of variation of the characteristics of an individual organism. In other words, this is the limit of the possibilities of modification variability. The phenotype is formed due to the interaction between the genotype and a number of factors of the internal and environmental.
The concept of genetic variation
A genotype is a collection of fragments that are called genes. This term includes the term genetic variation. This form of change of characters is divided into combinational and mutational.
Variability of a combinatorial nature occurs due to the exchange of identical (homologous) fragments of chromosomes. This phenomenon occurs during meiosis - sexual reproduction of cells. Key processes are:
- Independent divergence of chromosomal structures during meiotic division.
- Arbitrary association of chromosomes during fertilization.
- The course of conjugation (a process in which homologous chromosomes exchange sites).
About mutation
Genotype change is the process of transforming sequences into records of specific DNA components responsible for storing data on proteins and various types of RNA. Mutational variability is the basis of the change process. Mutations include a number of spasmodic and persistent changes in hereditary units - genes. They entail a hereditary change in the characteristics transmitted to the subsidiary organism. Also, mutations are not associated with the phenomenon of crossbreeding or gene recombination and are transmitted as hereditary information.
A mutation can be called a change in genotype. This phenomenon is divided into two types: gene and chromosomal. Chromosomal mutation is based on a change in its structure. An example is a change in the chromosome multiplicity of a haploid set. Heteroploidy leads to Down Syndrome (47 x.) Or Shereshevsky-Turner Syndrome (45 x., And one X chromosome is absent).
Mutations of genes affect the structure of the gene itself and lead to a change in the qualitative characteristics of the body. Such diseases can serve as an example: hemophilia, color blindness, albinism, etc. This type of change in the information contained in DNA is observed in cells of both somatic and sexual types, but only generative mutations are inherited. They are associated with changes in information in sperm, sperm and ova.
So, we can summarize that the definition of a genotype is a set and a common set of all gene regions. In organisms that reproduce sexually, in most cases cells contain two alleles of the same trait, with the exception of some especially important proteins, etc. They are divided into dominant and recessive and are important components of the process of evolutionary development of both humans and genotypes.
Genotype and viruses
There is a special form of life - viruses. These are organisms that can exhibit the properties of a living one only when they enter another living organism. They lead a parasitic lifestyle, and an example is adenovirus, HIV, HPV. The genotype is data about the body, which are available not only in cellular life forms, but also extracellular.
Determining the genotype of the virus is an extremely important work, since it allows you to determine the most effective measures to combat and counter it.