What are genotypes? The importance of the genotype in the scientific and educational spheres

Genetics has more than once amazed us with its achievements in the field of studying the genome of man and other living organisms. The simplest manipulations and calculations do not do without generally accepted concepts and signs, which do not deprive this science.

What are genotypes?

The term is understood to mean a set of genes of one organism that are stored in the chromosomes of each of its cells. The concept of a genotype should be distinguished from the genome, since both words carry a different lexical meaning. So, the genome is absolutely all genes of this species (human genome, monkey genome, rabbit genome).

How is the human genotype formed?

What is the genotype in biology? Initially, it was assumed that the set of genes of each body cell is different. This idea was refuted from the moment when scientists discovered the mechanism of formation of a zygote from two gametes: male and female. Since any living organism is formed from a zygote by multiple divisions, it is not difficult to guess that all subsequent cells will have an absolutely identical set of genes.

However, it is necessary to distinguish the parents' genotype from that of the child. The embryo in the mother's womb has half the set of genes from the mother and father, so the children, although similar to their parents, but at the same time are not their 100% counterparts.

What is the genotype and phenotype? What is their difference?

The phenotype is the totality of all external and internal signs of the organism. Examples include hair color, the presence of freckles, growth, blood type, the amount of hemoglobin, the synthesis or absence of an enzyme.

However, the phenotype is not something definite and permanent. If you watch the hares, then the color of their wool varies depending on the season: in the summer they are gray, and in the winter they are white.

It is important to understand that the set of genes is always permanent, and the phenotype can vary. If we take into account the vital activity of each individual cell in the body, any of them carries an absolutely identical genotype. However, one synthesizes insulin, another keratin, the third actin. Each is not similar to each other in form and size, functions. This is called phenotypic manifestation. That's what genotypes are and what are their differences from the phenotype.

This phenomenon is explained by the fact that when differentiating germ cells, some genes are included in the work, while others are in a "sleep mode". The latter or all their lives remain inactive, or are reused by the cell in stressful situations.

Examples of recording genotypes

In practice, the study of hereditary information is carried out using conditional gene coding. For example, the gene of brown eyes is written with a large letter "A", and the blue eyes - a small letter "a". So show that the sign of the dominant is dominant, and the blue color is a recessive.

So, on the basis of people can be:

• Dominant homozygotes (AA, brown-eyed);
• Heterozygotes (Aa, brown-eyed);
• Recessive homozygotes (aa, blue-eyed).

By this principle, the interaction of genes with each other is studied, and several pairs of genes are usually used at once. Hence the question arises: what is the 3 genotype (4/5/6, etc.)?

Such a phrase means that three pairs of genes are taken at once. The record will be, for example, the following: AaBBC. Here there are new genes that are responsible for completely different signs (for example, straight hair and curls, the presence of protein or its absence).

Why is a typical genotype record conditional?

Any gene discovered by scientists has a specific name. Most often these are English terms or phrases, which can reach considerable lengths in length. The orthography of names is difficult for representatives of foreign science, so scientists have introduced a simpler record of genes.

Even a high school student can sometimes know what genotype 3a is. Such a record means that three alleles of the same gene are responsible for the gene. When using the real name of the gene, understanding the principles of heredity could be difficult.

If we are talking about laboratories where serious studies of karyotype and DNA are being conducted, then the official names of genes are resorted to. This is especially true for those scientists who publish the results of their research.

Where genotypes are used

Another positive feature of using simple notations is universality. Thousands of genes have their own unique name, but each of them can be represented only by the letter of the Latin alphabet. In the overwhelming majority of cases, when solving genetic problems for different characteristics, the letters are repeated again and again, with each time the meaning is deciphered. For example, in one task gene B is the black color of hair, and in another it is the presence of a mole.

The question "what is genotypes" is raised not only in biology classes. In fact, the conventionality of designations causes the vagueness of formulations and terms in science. Roughly speaking, the use of genotypes is a mathematical model. In real life, everything is more complicated, despite the fact that the general principle still managed to be transferred to paper.

By and large, genotypes in the form in which we know them are used in the program of school and university education in solving problems. This simplifies the understanding of the topic "what are genotypes" and develops the students' ability to analyze. In the future, the skill of using such a record is also useful, however, in real research, these terms and gene names are more appropriate.

Currently, genes are being studied in various biological laboratories. Encryption and use of genotypes is relevant for medical consultations, when one or more of the traits are traced in a number of generations. At the output, specialists can predict a phenotypic manifestation in children with a certain probability (for example, the appearance in 25% of cases of blondes or the birth of 5% of children with polydactyly).