What are types of genotype in human beings? Different types of genotype - how many types of genotype we have?
What is genotype? Genotype and phenotype? Genotype - a set of all genes of the cells (of the body), localized in the nucleus (chromosomes) or in different replicate structures in the cytoplasm (mitochondria, plastids, and plasmids, etc.). Organisms with the same genotype of the system under development in different external conditions may see the arise of sharply distinctive features, that is the type of genotype characterized by the norm of reaction.
Norm of reaction occurs in response to any fluctuations in the environment, where there is the development of an organism. For example, red flowers of the primrose, which are grown at ambient temperatures of 15-20 °C, change into white when kept at an ambient temperature of 30-35 °C and high humidity.
From where do we get our genotypes? The response is obvioutools from our parents.
• GENOTYPE AA
• GENOTYPE AS
• GENOTYPE SS
• GENOTYPE AC
Adjusting of the system of a genotype to different conditions determines its ability to survive intensive breeding. Since different species have different genotype adaptability, there is a constant natural selection.
Homozygous organisms have a lower suitability compared to more heterozygous ones, and are subject to natural selection. The number and variety of types of genotype are important characteristics of viability of populations and their changes over time.
Type of genotype and blood group connection
It is established that four groups of human blood are stipulated by the inheritance of three alleles of a single gene (Ja, Jb, i). Thus I(0) group is stipulated by a recessive allele (i) which is dominated by the as allele Ja, defining group II, and allele B, which depends on group III. Alleles Ja and Jb in the heterozygotes determine IV group, that is, where there is a codominance. Thus:
I blood type happens only with genotype ii;
II — with genotypes Ja, Ja and Jai;
III — when genotypes Jb, Jb and Jbi;
IV - with genotype Ja, Jb.
The principle of inheritance of blood group is used for concealed cases of forensic examination in order to exclude paternity. It is necessary to remember the following. By blood it is impossible to establish that this man is the father of the child. We can only say, if he could be the father of the child or paternity is excluded.
Genotype - is a holistic system, where all genes interact with each other, influence each other and form a specific phenotype.
Therefore, each gene display depends on its genetic environment. Genes in the genotypebmay be:
• epistatic - suppressing the effects of other nonallelic genes;
• hypostatic - suppressing the genes of another allelic pair;
• pleiotropic genes - can affect the display of multiple characteristics simultaneously;
• lethal genes - those that reduce the viability of the embryo, even to his death;
• sub-lethal genes - significantly reduce the viability of the individual, cause death before the beginning of the reproductive period;
• modifiers - alter the display of another gene; mutator - those that dramatically change some of the characteristics of the organism.
In different systems of genes frequency of mutation is different:
• some have a relatively high mutability
• others mutate quite rarely.
Natural mutations in humans arise quite often. For example, mutation of albinism is described in all races of men. From haemophilia of type A suffer from 120 to 160 people per 1 million population, the frequency of haemophilia of B type in much lower - about 10-15 people per 1 million male population.
Types of genotypes determine individual human reaction to drugs, development of immunity, the perception of certain chemical compounds, the ontogenetic characteristics of the individual, it should be taken into account when prescribing drugs and their dosage.