Genotype and phenotype are the relationship between them. What are genotypes? The importance of genotype in the scientific and educational spheres

This is the totality of all the genes of an organism, which are its hereditary basis.

The totality of all signs and properties of an organism that are revealed in the process individual development in these conditions and are the result of the interaction of the genotype with a complex of internal and external environment.

Modifying variability does not cause changes in the genotype; it is associated with the reaction of a given, one and the same genotype to changes in the external environment: under optimal conditions, the maximum capabilities inherent in a given genotype are revealed. Modification variability manifests itself in quantitative and qualitative deviations from the original norm, which are not inherited, but are only adaptive in nature, for example, increased pigmentation of human skin under the influence of ultraviolet rays or development muscular system under the influence physical exercise etc.

Combinative variability arises as a result of the exchange of homologous regions of homologous chromosomes during the process of meiosis, which leads to the formation of new gene associations in the genotype. It arises as a result of three processes: 1) independent chromosome segregation during meiosis; 2) their random connection during fertilization; 3) exchange of sections of homologous chromosomes or conjugation. .

Mutational variability (mutations). Mutations are abrupt and stable changes in units of heredity - genes, entailing changes in hereditary characteristics. They necessarily cause changes in the genotype, which are inherited by the offspring and are not associated with crossing and recombination of genes.

There are chromosomal and gene mutations. Chromosomal mutations associated with changes in chromosome structure. This may be a multiple or non-fold change in the number of chromosomes haploid set(in plants - polyploidy, in humans - heteroploidy). An example of heteroploidy in humans is Down syndrome (one extra chromosome and in the karyotype there are 47 chromosomes), Shereshevsky-Turner syndrome (one X chromosome is missing, 45). Such deviations in a person’s karyotype are accompanied by health disorders, mental and physical disorders, decreased vitality, etc.

Genotype and phenotype.

Genotype– a set of hereditary characteristics and properties received by an individual from its parents. As well as new properties that appeared as a result of gene mutations that the parents did not have. The genotype is formed through the interaction of two genomes (egg and sperm) and represents a hereditary development program, being an integral system, and not a simple sum of individual genes. The integrity of the genotype is the result of evolutionary development, during which all genes were in close interaction with each other and contributed to the preservation of the species, acting in favor of stabilizing selection. Thus, a person’s genotype determines (determines) the birth of a child, a hare’s offspring will be represented by hares, and only sunflower will grow from sunflower seeds.

Genotype– it’s not just the sum of genes. The possibility and form of gene manifestation depend on environmental conditions. The concept of environment includes not only the conditions surrounding the cell, but also the presence of other genes. Genes interact with each other and, once in the same genotype, can greatly influence the manifestation of the action of neighboring genes.

Phenotype- the totality of all the characteristics and properties of an organism that have developed in the process of individual development of the genotype. This includes not only external signs(color of skin, hair, shape of ear or nose, color of flowers), but also internal: anatomical (body structure and relative arrangement of organs), physiological (shape and size of cells, structure of tissues and organs), biochemical (protein structure, enzyme activity, concentration of hormones in the blood). Each individual has its own characteristics appearance, internal structure, the nature of metabolism, the functioning of organs, i.e. your phenotype, which was formed under certain environmental conditions.

If we consider the results of self-pollination of F2 hybrids, we can find that plants grown from yellow seeds, although externally similar and having the same phenotype, have a different combination of genes, i.e.

Genotype and phenotype, their variability

different genotype.

Concepts genotype and phenotype– very important in genetics. The phenotype is formed under the influence of the genotype and environmental conditions.

It is known that the genotype is reflected in the phenotype, and the phenotype is most fully manifested under certain environmental conditions. Thus, the manifestation of the gene pool of a breed (variety) depends on environment, i.e. conditions of detention ( climatic factors, care). Often varieties developed in some areas are not suitable for cultivation in others.

Phenotype and genotype - their differences

The genotype is the totality of all the genes of an organism, which are its hereditary basis.

Phenotype is a set of all signs and properties of an organism that are revealed during the process of individual development under given conditions and are the result of the interaction of the genotype with a complex of factors of the internal and external environment.

Phenotype in general case- this is what can be seen (cat color), heard, felt (smell), as well as the behavior of the animal. Let's agree that we will consider the phenotype only from the point of view of color.

As for the genotype, they most often talk about it, meaning a certain small group of genes. For now, let's assume that our genotype consists of just one gene W(in the following paragraphs we will sequentially add other genes to it).

In a homozygous animal, the genotype coincides with the phenotype, but in a heterozygous animal, it does not.

Indeed, in the case of genotype WW, both alleles are responsible for white color, and the cat will be white. Likewise ww- both alleles are responsible for non-white color, and the cat will not be white.

But in the case of genotype Ww the cat will be externally (phenotypically) white, but in its genotype it will carry a recessive allele not white color w.

Every biological species has a phenotype unique to it. It is formed in accordance with the hereditary information contained in the genes. However, depending on changes in the external environment, the state of traits varies from organism to organism, resulting in individual differences - variability.

Based on the variability of organisms, genetic diversity of forms appears. A distinction is made between modificational, or phenotypic, and genetic, or mutational variability.

Modifying variability does not cause changes in the genotype; it is associated with the reaction of a given, one and the same genotype to changes in the external environment: under optimal conditions, the maximum capabilities inherent in a given genotype are revealed. Modification variability manifests itself in quantitative and qualitative deviations from the original norm, which are not inherited, but are only adaptive in nature, for example, increased pigmentation of human skin under the influence of ultraviolet rays or the development of the muscular system under the influence of physical exercise, etc.

The degree of variation of a trait in an organism, that is, the limits of modification variability, is called the reaction norm. Thus, the phenotype is formed as a result of the interaction of the genotype and environmental factors. Phenotypic characteristics are not transmitted from parents to offspring, only the reaction norm is inherited, that is, the nature of the response to changes in environmental conditions.
Genetic variability can be combinative and mutational.

1) independent chromosome segregation during meiosis;
2) their accidental combination during fertilization;
3) exchange of sections of homologous chromosomes or conjugation.

Mutational variability.

What is genotype and phenotype

Mutations are abrupt and stable changes in units of heredity - genes, entailing changes in hereditary characteristics. They necessarily cause changes in the genotype, which are inherited by the offspring and are not associated with crossing and recombination of genes.
There are chromosomal and gene mutations. Chromosomal mutations are associated with changes in the structure of chromosomes. This may be a change in the number of chromosomes that is a multiple or not a multiple of the haploid set (in plants - polyploidy, in humans - heteroploidy). An example of heteroploidy in humans can be Down syndrome (one extra chromosome and 47 chromosomes in the karyotype), Shereshevsky-Turner syndrome (one X chromosome is missing, 45). Such deviations in a person’s karyotype are accompanied by health disorders, mental and physical disorders, decreased vitality, etc.

Gene mutations- affect the structure of the gene itself and entail a change in the properties of the body (hemophilia, color blindness, albinism, etc.). Gene mutations occur in both somatic and germ cells.
Mutations that occur in germ cells are inherited. They are called generative mutations. Changes in somatic cells cause somatic mutations that spread to that part of the body that develops from the changed cell. For species that reproduce sexually, they are not essential; for vegetative propagation of plants they are important.

Phenotype

What is a Phenotype? The meaning of the word in popular dictionaries and encyclopedias, as well as:

History of the term "Phenotype";
Examples of use in everyday life;
Synonyms and similar words.

The meaning of "Phenotype" in dictionaries

Phenotype–Psychological Dictionary (from Greek - I appear, show up + typos – imprint, image) is a set of characteristics of an organism formed under the influence of genetic factors and environmental factors in which its individual development took place (see Genotype). Phenotype–Psychological Dictionary (Greek phaino - manifest, manifest + type). The totality of all the properties and characteristics of an individual, formed at a certain stage of development as a result of the interaction of the genotype with the environment. Phenotype - Psychological Encyclopedia (from the Greek - phaino - I appear, appear and typos - imprint, image) - changes in genotypic characteristics due to the course of individual life activity under certain environmental influences. Phenotype – Sociological Dictionary - English. phenotype; German Phanotyp. czech/epo?ur. The totality of all the properties and characteristics of an organism formed in the process of its individual development (ontogenesis); F. is determined by the interaction of the genotype (i.e., the hereditary basis of the organism) with the environmental conditions in which its development occurs. See GENOTYPE. Phenotype – Big Encyclopedic Dictionary (from the Greek pheno and type) - in biology - the totality of all the signs and properties of an organism formed in the process of its individual development. It develops as a result of the interaction of the hereditary properties of the organism - genotype and environmental conditions. Phenotype - Psychological Dictionary Word formation. Comes from the Greek. - phaino - I appear, show myself and typos - imprint, image. Category. Changes in genotypic characteristics caused by the course of individual life activity under certain environmental influences. Phenotype – Psychological Dictionary Observable characteristics or traits of an individual organism. It is usually compared with the genotype, i.e., with genetic information that is passed on from generation to generation. Phenotype – Psychological Dictionary (phenotype) is the totality of all signs and properties inherent in an individual that were formed in the process of his individual development. occurs as a result of the interaction between an individual's genotype and the environment. Phenotype–Psychological Dictionary Factual, physical, observable; the manifest structure, function, or behavior of an organism. For more details, see genotype. Phenotype - Psychological Dictionary - any observable characteristic of an organism - morphological, physical, behavioral. The term was proposed in 1909 by the Danish biologist V. Johannsen. - a product of the interaction of genotype and environment, but on different levels organization - cellular, organ, organism - the relationship between phenotype and genotype is different. According to I.P. Pavlov, a phenotype is a pattern of activity of the higher nervous system, formed as a result of a combination congenital features and conditions of education. This concept is related to the concept of character.

Human genotype and phenotype - what are these concepts?

It is not customary to denote the totality of a person’s social characteristics with this term. Phenotype–Sociological Dictionary is a set of properties formed from genotypic individual properties developing during the life process. Phenotype–Philosophical Dictionary (from the Greek phaino + type) is a set of all signs and properties of an organism formed in the process his individual development. It is determined primarily by the genetic heredity of the organism (its genotype) and the specific environmental conditions in which ontogenesis takes place, including, first of all, its upbringing, education and spiritual formation. As a result of this, all observable characteristics of the organism, its behavior and lifestyle, interaction with the environment and the noosphere are formed. changes somewhat during the life of an individual due to changes in the environment, physiological and morphological changes associated with aging of the body. Various environments habitats, in turn, can have different influence on the formation of an individual’s hereditary traits, since his physical condition, for example, largely depends on the completeness and rationality of nutrition, as well as changing the behavioral manifestation of the genotypes themselves (examples include twins raised in different families). Phenotype–Philosophical Dictionary (from the Greek phдinon - being and typos - imprint) - the totality of all signs and properties of an organism formed in the process of its individual development, as opposed to its hereditary properties, its genotype. See also Origin of species theory.

Phenotype is the totality of all the characteristics and properties inherent in an individual that were formed in the process of his individual development. Phenotype results from the interaction between an individual's genotype and the environment. Medical Dictionary

Genotype and phenotype

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Phenotype

Phenotype (from Greek word phaino - manifest, discover) - the totality of all the signs and properties of an organism formed in the process of its individual development. The phenotype is formed as a result of the interaction of the hereditary properties of the organism-genotype and environmental conditions.

The cell nuclei contain a set of chromosomes received from the parents that carry a set of genes that are characteristic of a given species in general and for of a given organism in particular. These genes carry information about proteins that can be synthesized in this organism, as well as about the mechanisms that determine the synthesis itself and its regulation (see Transcription, Translation).

During the process of development (see Ontogenesis), genes are sequentially switched on and the proteins they encode are synthesized (gene expression). As a result, all the signs and properties of the organism develop, which make up its phenotype.

Thus, a phenotype is a product of the implementation of the genetic program contained in the genotype.

However, the genotype does not unambiguously determine the phenotype; to a greater or lesser extent, it also depends on external conditions. Sometimes phenotypes differ extremely dramatically in different conditions. For example, the Arashnia butterfly produces two generations of new butterflies per year.

Phenotype: definition, examples, relationship with genotype and genetic diversity

Spring butterflies emerging from overwintered pupae are very different from butterflies with the same genotype developing in summer (they were previously considered different types). The pines in the forest are tall and slender, but in the open space they are spreading. The shape of water buttercup leaves depends on whether the leaf is in the water or in the air.

The ability to change the phenotype provided genetic program, is called the reaction norm. Typically, the more diverse the habitat conditions of a species, the wider its reaction norm.

If environmental conditions differ sharply from those to which the species is adapted, the development of the organism is disrupted and it dies.

Recessive alleles are not always reflected in the characteristics of the phenotype, but are preserved and can be transmitted to offspring. This is important to know for understanding the mechanism of evolution, since natural selection acts only on phenotypes, and genotypes are selected, i.e., transmitted to the offspring and remain in the population.

The relationship between genotype and phenotype is not limited to the interaction of dominant and recessive alleles, but includes the interaction of many genes with each other. The mechanisms of these interactions in the development of the organism, as well as the mechanisms of development in general, are largely unclear. But the very division of the single concept of heredity into two - genotype and phenotype, actually carried out by G. Mendel (he did not know these terms), was a great discovery in biology.

Definition: phenotype - the expressed physical traits of an organism determined by genotype, random genetic variation, and environmental influences.

Examples: traits such as color, height, size, shape and behavior.

The relationship between phenotype and genotype

The genotype of an organism determines its phenotype. All living organisms have DNA, which provides instructions for the production of molecules, tissues and organs. DNA contains the genetic code, which is also responsible for directing all cellular functions, including DNA replication, protein synthesis, and molecular transport.

An organism's phenotype (physical traits and behavior) is determined by its inherited genes. are certain sections of DNA that encode the structure of proteins and determine various signs. Each gene is located on and can exist in more than one form. These various shapes called alleles, which are located in certain places on certain chromosomes. Alleles are passed from parents to offspring through.

Diploid organisms inherit two alleles for each gene; one allele from each parent. The interactions between alleles determine the phenotype of an organism. If an organism inherits two identical alleles for a particular trait, it is homozygous for that trait. Homozygous individuals express one phenotype for of this characteristic. If an organism inherits two different alleles for a particular trait, it is heterozygous for that trait. Heterozygous individuals can express more than one phenotype for a given trait.

Traits may or may not be recessive. In inheritance patterns of complete dominance, the phenotype dominant trait completely masks the phenotype of a recessive trait. There are also cases where the relationship between different alleles does not show complete dominance. In incomplete dominance, the dominant allele does not completely mask the other allele. This results in a phenotype that is a mixture of the phenotypes observed in both alleles. With codominance, both alleles are fully expressed. This results in a phenotype in which both traits are observed independently of each other.

Complete, incomplete and co-dominance

Phenotype and genetic diversity

May influence phenotypes. It describes changes in the genes of organisms in a population. These changes may be the result of DNA mutations. Mutations are changes to gene sequences in DNA.

Any change in gene sequence can alter the phenotype expressed by the inherited alleles. Gene flow also contributes to genetic diversity. When new organisms enter a population, new genes are introduced. The introduction of new alleles into the gene pool makes new gene combinations and different phenotypes possible.

During time, various combinations of genes are formed. In meiosis, they are randomly divided into different ones. Gene transfer can occur between homologous chromosomes through the process of crossing. This gene recombination can create new phenotypes in a population.

The genotype is the totality of all the genes of an organism, which are its hereditary basis.

Each biological species has a phenotype unique to it. It is formed in accordance with the hereditary information contained in the genes. However, depending on changes in the external environment, the state of traits varies from organism to organism, resulting in individual differences - variability.

Based on the variability of organisms, genetic diversity of forms appears. A distinction is made between modificational, or phenotypic, and genetic, or mutational variability.

Modifying variability does not cause changes in the genotype; it is associated with the reaction of a given, one and the same genotype to changes in the external environment: under optimal conditions, the maximum capabilities inherent in a given genotype are revealed. Modification variability manifests itself in quantitative and qualitative deviations from the original norm, which are not inherited, but are only adaptive in nature, for example, increased pigmentation of human skin under the influence of ultraviolet rays or the development of the muscular system under the influence of physical exercise, etc.

Genetic variability can be combinative and mutational.

There are chromosomal and gene mutations. Chromosomal mutations are associated with changes in the structure of chromosomes. This may be a change in the number of chromosomes that is a multiple or not a multiple of the haploid set (in plants - polyploidy, in humans - heteroploidy). An example of heteroploidy in humans can be Down syndrome (one extra chromosome and 47 chromosomes in the karyotype), Shereshevsky-Turner syndrome (one X chromosome is missing, 45). Such deviations in a person’s karyotype are accompanied by health disorders, mental and physical disorders, decreased vitality, etc.

Gene mutations affect the structure of the gene itself and entail changes in the properties of the body (hemophilia, color blindness, albinism, etc.). Gene mutations occur in both somatic and germ cells.

Mutations that occur in germ cells are inherited. They are called generative mutations. Changes in somatic cells cause somatic mutations that spread to that part of the body that develops from the changed cell. For species that reproduce sexually, they are not essential; for vegetative propagation of plants they are important.

Let us recall once again the meaning of the concepts of genotype and phenotype. The genotype is the totality of all the genes of a given organism; a phenotype is the totality of all the characteristics of an organism.

It is known that with the same phenotype, organisms can have different genotypes. For example, in Mendel's experiments, plants whose genotype contained AA alleles and plants whose genotype contained Aa alleles did not differ from each other in phenotype. Could there be the opposite situation, when the genotypes of organisms are the same, but the phenotypes are different? In particular, to what extent is the phenotype determined by the genotype, and to what extent by environmental influences? This issue is often discussed at the everyday level in relation to the character or behavior of people. There are two points of view.

According to one of them, a person’s characteristics are entirely determined by his genotype. Behavior is determined by heredity, with which nothing can be done. According to another point of view, heredity in human behavior plays a minor role in comparison with living conditions and, especially, upbringing.

Let us consider the influence of heredity and environment on more simple signs than people's behavior. Even for such signs, different options are possible.

Some traits are completely determined by the genotype and do not depend on environmental conditions. These include, for example, blood groups and many genetic diseases.

Other traits depend on both the genotype and the environment. For example, a person's height depends on his genotype (remember Galton's work). At the same time, growth also depends on environmental conditions, in particular on nutrition during the growth period. Skin color is largely determined by genotype. But the skin color of people with the same genotype very much depends on the time they spend in the sun (Fig. 122).

Let us consider several typical examples of the influence of the environment on the expression of genes.

1. Still for real early period development of genetics, it was discovered that a trait can be dominant or recessive depending on the conditions in which the organism develops. In 1915, Morgan showed on Drosophila that when grown in dry air, the distribution of stripes on the abdomen of the Drosophila, which is normal for the “wild” type, dominates over the abnormal one, and, on the contrary, when there is excess humidity, the abnormal distribution of stripes dominates. Observations of this kind once again showed the differences between genotype and phenotype: with the same genotype, the phenotype depended on external conditions.

2. The influence of the external environment on phenotype can be demonstrated using the example of social insects. In bees and ants, males develop from unfertilized eggs, and females from fertilized eggs. However, the phenotype of these females depends on developmental conditions: under some conditions, a fertile female develops, and under others, an infertile worker bee develops. Ants have different “castes” of sterile individuals. The main part of the anthill population is made up of worker ants, who build the anthill, get food, feed the larvae and do all sorts of other work. Many species of ants have “soldiers” - ants with a large head, protected by thick chitin, and with especially powerful jaws. Worker ants and soldiers are underdeveloped females and are sterile. Why do some eggs laid by a female produce working individuals, others - soldiers, and others - winged sexual individuals: males and females? Back in 1910, ant researcher Wassman removed a female from a nest. It turned out that after this the worker ants begin to lay eggs! This experiment showed that the presence of a female inhibits the laying of eggs by working individuals. Upon further study, it turned out that in addition to substances that inhibit the development of new females, substances circulate in the anthill that, on the contrary, stimulate the development of ovaries in workers and larvae. These substances are produced by special glands of worker ants. IN normal conditions worker ants feed these substances to the queen and larvae, from which males and females develop. If there is no queen in the anthill, these substances are received mainly by the larvae. If there are few larvae, then the worker ants feed each other with these substances and then begin to lay eggs. Thus, it was found that the development of the larvae depends on what food they receive from working ants and what additives are in the food. In the same way, in bees, the nature of the food and additives determines whether the larva will develop into a worker bee or into a queen bee.

3. Ermine rabbits have white fur, but certain parts of the body - paws, ears, tip of the muzzle and tail - are black. If you cut off an area on a rabbit's back, which is covered with white fur, and keep the rabbit at a low temperature, black hair will grow on this area. Of course, such spots of black color on unusual place the descendants of this rabbit are not inherited.

The examples given show that in reality, in many cases, it is not the trait as such that is inherited, but the ability to develop a given trait under appropriate environmental conditions, which is passed on from generation to generation.

Genotype– a set of hereditary characteristics and properties received by an individual from its parents. As well as new properties that appeared as a result of gene mutations that the parents did not have. The genotype is formed by the interaction of two (egg and sperm) and represents a hereditary development program, being an integral system, and not a simple sum of individual genes. The integrity of the genotype is the result of development, during which all genes were in close interaction with each other and contributed to the preservation of the species, acting in favor of stabilizing selection. Thus, a person’s genotype determines (determines) the birth of a child, a hare’s offspring will be represented by hares, and only a sunflower will grow from a sunflower.

Genotype– it’s not just the sum of genes. The possibility and form of gene manifestation depend on environmental conditions. The concept of environment includes not only the conditions surrounding the cell, but also the presence of other genes. Genes interact with each other and, once in one, can greatly influence the manifestation of the action of neighboring genes.

Phenotype- the totality of all the characteristics and properties of an organism that have developed in the process of individual development of the genotype. This includes not only external signs (skin color, hair, shape of ear or nose, color of flowers), but also internal ones: anatomical (body structure and relative arrangement of organs), physiological (shape and size of cells, structure of tissues and organs), biochemical ( protein structure, enzyme activity, concentration of hormones in the blood). Each individual has its own characteristics of appearance, internal structure, nature of metabolism, functioning of organs, i.e. your phenotype, which was formed under certain environmental conditions.

If we consider the results of self-pollination F2, we can find that plants grown from yellow seeds, although externally similar and having the same phenotype, have a different combination of genes, i.e. different genotype.

Concepts genotype and phenotype– very important in . The phenotype is formed under the influence of the genotype and environmental conditions.

It is known that the genotype is reflected in the phenotype, and the phenotype is most fully manifested under certain environmental conditions. Thus, the manifestation of the gene pool of a breed (variety) depends on the environment, i.e. conditions of detention (climatic factors, care). Often varieties developed in some areas are not suitable for cultivation in others.