What is the totality of hereditary properties of an organism called? The set of hereditary properties of an organism

Genome call the entire set of hereditary material contained in the haploid set of chromosomes of the cells of a given type of organism. The genome is species-specific, since it represents the necessary set of genes that ensures the formation of species-specific characteristics of organisms during their normal ontogenesis. For example, some species develop haploid organisms that develop from a single set of genes contained in the genome. Thus, in a number of arthropod species, males are haploid, developing from unfertilized eggs.

During sexual reproduction, the genomes of two parental germ cells combine during fertilization, forming genotype new organism. All somatic cells of such an organism have a double set of genes received from both parents in the form of certain alleles. Thus, the genotype is the genetic constitution of an organism, which is the totality of all the hereditary inclinations of its cells contained in their chromosomal set - the karyotype.

Rice. 3.67. Karyotypes of organisms of various species:

I- skurdy, II- Drosophila. III - person

Karyotype - a diploid set of chromosomes characteristic of somatic cells of organisms of a given species, which is a species-specific feature and is characterized by a certain number, structure and genetic composition of chromosomes (Fig. 3.67). Below are the chromosome numbers of somatic cells of some types of organisms.

If the number of chromosomes in a haploid set of germ cells is denoted p, That general formula the karyotype will look like 2p, where is the value n different for different types. Being species characteristics organisms, the karyotype may differ in certain individuals in some particular features. For example, representatives of different sexes have basically the same pairs of chromosomes ( autosomes), but their karyotypes differ in one pair of chromosomes ( heterochromosomes, or sex chromosomes). Sometimes these differences are different quantities heterochromosomes in females and males (XX or XO). Most often, the differences relate to the structure of the sex chromosomes, designated in different letters-X and Y (XX or XY).

Each type of chromosome in the karyotype, containing a specific set of genes, is represented by two homologues inherited from the parents with their germ cells. A double set of genes contained in a karyotype - a genotype is unique combination paired genome alleles. The genotype contains the development program of a particular individual.

- (from Gene and Type) the totality of all genes localized in the chromosomes of a given organism. In a broader sense, genetics is the totality of all hereditary factors of an organism - both nuclear (genome) and non-nuclear, extrachromosomal (i.e. Great Soviet Encyclopedia